This leftover ham tater tot casserole turns yesterday’s holiday ham into a crispy-topped, cheese-loaded comfort dish that’ll have everyone asking for seconds. My leftover ham tater tot casserole combines smoky ham chunks, creamy vegetables, and golden tater tots into a one-pan wonder that makes weeknight cooking feel like a celebration.
SERVES: 4 | PREP: 15 MIN | COOK: 45 MIN | TOTAL: 60 MIN
Why This Leftover Ham Tater Tot Casserole Works
I created this recipe after staring at a mountain of leftover Easter ham and realizing I needed something my kids would actually eat. The crispy tater tot topping seals in all the creamy goodness underneath, while the cheese creates pockets of melted heaven throughout the casserole.
The secret is layering everything strategically so the flavors build on each other. You get smoky ham in every bite, vegetables that stay tender but not mushy, and those tater tots crisp up perfectly on top while the bottoms soak up just enough sauce to stay interesting.
Ingredients
For the Ham Base
| Ingredient | Amount |
|---|---|
| Leftover cooked ham, diced | 3 cups |
| Frozen mixed vegetables | 2 cups |
| Yellow onion, diced | 1 medium |
| Garlic cloves, minced | 3 cloves |
| Butter | 2 tablespoons |
For the Creamy Sauce
| Ingredient | Amount |
|---|---|
| Cream of mushroom soup | 1 can (10.5 oz) |
| Sour cream | 1 cup |
| Whole milk | ½ cup |
| Dijon mustard | 1 tablespoon |
| Black pepper | ½ teaspoon |
| Garlic powder | ½ teaspoon |
For the Topping
| Ingredient | Amount |
|---|---|
| Frozen tater tots | 4 cups (about 1 lb) |
| Sharp cheddar cheese, shredded | 2 cups |
| Fresh parsley, chopped | 2 tablespoons |
Step-by-Step Instructions
Phase 1: Prep Work (5 minutes)
Step 1: Prepare Your Oven and Pan
Preheat your oven to 375°F and grab a 9×13-inch baking dish. I like to give mine a light spray with cooking oil even though this casserole has plenty of fat – it just makes cleanup easier when that cheese inevitably bubbles over the edges.
The 375°F temperature is perfect because it’s hot enough to crisp those tater tots but gentle enough that the sauce won’t break or curdle underneath.
Step 2: Dice Your Ham
Cut your leftover ham into ½-inch cubes – this size is important because smaller pieces disappear into the sauce while larger chunks don’t heat through evenly. You want 3 cups of diced ham, which is about 1 pound or roughly a quarter of a standard holiday ham.
If your ham has a thick fatty edge, trim most of it off but leave a little – that fat adds flavor as it renders.
Step 3: Prep Your Vegetables
Dice 1 medium yellow onion into small pieces about ¼-inch across. Mince 3 garlic cloves finely – I use a garlic press because it distributes the flavor more evenly through the sauce.
Pull your 2 cups frozen mixed vegetables from the freezer but don’t thaw them. Frozen vegetables work better here because they release less water during baking.
Phase 2: Building the Base (10 minutes)
Step 4: Sauté the Aromatics
Melt 2 tablespoons butter in a large skillet over medium heat. When the butter stops foaming and smells nutty, add your diced onion.
Cook for 4-5 minutes, stirring occasionally, until the onion turns translucent and soft. You’ll know it’s ready when the pieces bend easily and have lost their sharp raw smell.
Step 5: Add Garlic and Ham
Toss in your minced garlic and stir constantly for 30 seconds – just until it smells fragrant. Garlic burns quickly, so watch it carefully.
Add your 3 cups diced ham to the pan and stir everything together. Cook for 2 minutes to warm the ham through and let it pick up some of that buttery onion flavor. The ham doesn’t need to brown since it’s already cooked.
Step 6: Incorporate the Vegetables
Dump in your 2 cups frozen mixed vegetables straight from the freezer. Stir them into the ham mixture and cook for 2-3 minutes, just until the frozen glaze melts off.
The vegetables will release a bit of steam – that’s normal and actually helps deglaze any browned bits from the bottom of your pan. Turn off the heat and set this mixture aside.
Phase 3: Creating the Sauce (5 minutes)
Step 7: Mix Your Creamy Base
In a large mixing bowl, combine 1 can cream of mushroom soup, 1 cup sour cream, and ½ cup whole milk. Whisk these together until completely smooth with no lumps of soup remaining.
The milk thins the mixture just enough so it coats everything evenly but isn’t runny. Don’t skip the whisking step or you’ll end up with pockets of thick soup in your finished casserole.
Step 8: Season Your Sauce
Add 1 tablespoon Dijon mustard, ½ teaspoon black pepper, and ½ teaspoon garlic powder to your creamy mixture. Whisk again until the mustard is fully incorporated – you shouldn’t see any yellow streaks.
The Dijon adds a subtle tang that cuts through the richness and complements the smokiness of the ham. I don’t add salt here because ham and canned soup are already salty enough.
Step 9: Combine Everything
Pour your ham and vegetable mixture into the bowl with your sauce. Fold everything together gently with a spatula until every piece of ham and vegetable is coated in that creamy mixture.
You’re looking for a consistency that’s thick but pourable – like a chunky gravy. If it seems too thick, add another 2 tablespoons milk.
Phase 4: Assembly and Baking (45 minutes)
Step 10: Layer Your Casserole Base
Spread your ham mixture evenly into your prepared 9×13-inch baking dish. Use your spatula to smooth it into an even layer, making sure to push it into all the corners.
An even layer is important here because it ensures consistent cooking – you don’t want thin spots that dry out or thick spots that stay cold in the center.
Step 11: Add the Cheese Layer
Sprinkle 1 cup shredded sharp cheddar cheese evenly over the ham mixture. I save the other cup for later because adding it all now would create a rubbery cheese barrier that prevents the tater tots from connecting with the sauce below.
The cheese will melt down into the sauce and create pockets of melted goodness that make every bite interesting.
Step 12: Arrange Your Tater Tots
Place your 4 cups frozen tater tots in tight, even rows across the top of the casserole. I like to arrange them in straight lines because it looks nice, but you can also just scatter them evenly if you’re in a hurry.
Press each tot down gently so the bottom makes contact with the cheese layer – this helps them stick to the casserole instead of rolling around when you serve it. Don’t thaw the tots first or they’ll turn mushy instead of crispy.
Step 13: Initial Bake
Slide your casserole into the preheated 375°F oven and bake uncovered for 30 minutes. During this time, the sauce will bubble up around the edges and the tater tots will start to turn golden.
Don’t open the oven door during this time – you’ll lose heat and extend your cooking time. Just watch through the oven window for bubbling sauce around the edges.
Step 14: Add Final Cheese Topping
After 30 minutes, carefully pull the casserole from the oven. Sprinkle the remaining 1 cup shredded cheddar cheese evenly over the tater tots.
The tater tots should be golden brown on top at this point. If they’re still pale, give them another 5 minutes before adding the cheese.
Step 15: Finish Baking
Return the casserole to the oven and bake for 15 more minutes, until the cheese melts completely and the tater tots are deep golden brown and crispy.
You’ll know it’s done when the edges are bubbling vigorously, the cheese on top is melted and starting to brown in spots, and the tater tots feel crisp when you tap one with a fork.
Step 16: Rest and Garnish
Remove the casserole from the oven and let it rest for 5 minutes before serving. This resting time lets the sauce thicken up slightly so it doesn’t run all over your plate when you scoop portions.
Sprinkle 2 tablespoons chopped fresh parsley over the top right before serving – the bright green color makes the whole dish look more appealing and the fresh herb flavor balances the richness.
Chef’s Notes
Leftover ham quality matters. Honey-glazed or brown sugar-crusted ham adds sweetness that plays beautifully against the savory sauce in this leftover ham tater tot casserole. Smoked ham gives you deeper flavor, while plain boiled ham works but might taste a bit flat. If you’re using plain ham, add an extra ½ teaspoon smoked paprika to the sauce for depth.
Vegetable flexibility is your friend. I use frozen mixed vegetables because they’re convenient and consistent, but you can absolutely use 2 cups of whatever vegetables you have hanging around. Frozen peas and carrots work great, as do fresh broccoli florets (blanched for 2 minutes first) or diced bell peppers. Just keep the total volume at 2 cups so the sauce ratio stays correct.
Cheese choice changes everything. Sharp cheddar gives you the best flavor punch, but I’ve made successful versions with Gruyère (fancy and nutty), pepper jack (if you like heat), or even a Mexican cheese blend. Avoid pre-shredded cheese if possible – it contains anti-caking agents that can make your sauce grainy. Shred a block yourself for the smoothest results.
Make-ahead trick for busy nights. Assemble the entire casserole through Step 12, cover tightly with plastic wrap, and refrigerate for up to 24 hours. When you’re ready to bake, add 10 minutes to the initial baking time since you’re starting from cold. This makes your leftover ham tater tot casserole perfect for meal prep or when you know tomorrow will be crazy.
Nutrition Information (Per Serving)
Calories: 685 | Protein: 32g | Carbohydrates: 48g | Fat: 41g | Saturated Fat: 18g | Fiber: 4g | Sodium: 1,850mg | Sugar: 6g
Tasty Variations
Southwest Ham Fiesta Casserole: Replace the mixed vegetables with 1 cup black beans (drained) and 1 cup corn kernels. Swap the cheddar for pepper jack cheese and add 1 teaspoon cumin and ½ teaspoon chili powder to the sauce. Top with crushed tortilla chips instead of tater tots for a completely different texture. This version pairs perfectly with my leftover ham panini for a week of Southwest-inspired ham meals.
Breakfast Hash Brown Casserole: Use frozen hash browns instead of tater tots and add 6 beaten eggs mixed into the sauce. Include 1 cup diced bell peppers in your vegetable mix and top with crumbled cooked bacon along with the cheese. Bake at 350°F for 50 minutes until the eggs are set in the center. Serve with hot sauce and you’ve got brunch covered.
Italian-Style Ham Bake: Stir 1 cup marinara sauce into your creamy mixture and add 1 teaspoon Italian seasoning. Use mozzarella instead of cheddar and top with ¼ cup grated Parmesan along with the tater tots. Serve with a side salad for a complete meal, or check out my leftover ham turnovers for another Italian-inspired ham transformation.
Loaded Baked Potato Casserole: Mix 4 slices cooked, crumbled bacon into the ham mixture and add 2 tablespoons chopped chives to the sauce. Use a combination of cheddar and Monterey Jack cheese, and serve each portion with a dollop of sour cream and extra chives on top. The flavors mimic a loaded baked potato but in casserole form.
Storage & Reheating
Refrigerator storage keeps this casserole fresh for 3-4 days in an airtight container. Let it cool completely before covering – trapping steam makes the tater tots soggy. I divide leftovers into individual portions in meal prep containers so I can grab one for lunch without reheating the whole pan.
Freezing works surprisingly well if you follow one rule: freeze it before baking rather than after. Assemble everything through Step 12, wrap the pan tightly in plastic wrap and then aluminum foil, and freeze for up to 2 months. Bake from frozen at 375°F for 1 hour 15 minutes, covering with foil for the first 45 minutes to prevent over-browning.
Reheating individual portions in the microwave takes 2-3 minutes at 70% power. Place a damp paper towel over the top to keep it from drying out, but don’t expect the tater tots to stay crispy – that’s just the reality of microwave reheating. For crispy tots, reheat in the oven at 350°F for 15 minutes.
Reheating the whole casserole requires 25 minutes at 350°F covered with foil, then 10 minutes uncovered to re-crisp the top. Add a splash of milk around the edges if it looks dry – the sauce can thicken considerably in the fridge.
Troubleshooting Common Problems
Problem: Watery casserole with a soupy bottom
You probably used thawed frozen vegetables or fresh vegetables that released too much water during baking. Always use frozen vegetables straight from the freezer – they release less liquid. If you prefer fresh vegetables, sauté them first in your skillet to drive off excess moisture before mixing them into the sauce. You can also reduce the milk by ¼ cup if your ham was particularly wet or if you live in a humid climate.
Problem: Tater tots stayed pale and soft instead of browning
Your oven temperature might be running low, or you crowded the tots too tightly together. Use an oven thermometer to verify your actual temperature – many ovens run 25°F cooler than the dial suggests. Space your tater tots with tiny gaps between them so hot air can circulate. If they’re still not browning after the full baking time, switch your oven to broil for 2-3 minutes at the end, watching carefully so they don’t burn.
Problem: Sauce separated or looks curdled
This happens when the sauce gets too hot too fast, usually from baking at too high a temperature or using low-fat dairy products. Always use full-fat sour cream and whole milk – the extra fat helps stabilize the sauce. Make sure your oven temperature is accurate, and don’t try to speed things up by cranking the heat. If your sauce does break, whisk in 2 tablespoons of heavy cream while the casserole is still hot to bring it back together.
Problem: Casserole is dry and the sauce disappeared
You either didn’t use enough sauce to begin with or you overbaked it. The sauce should look almost too liquidy when you pour it in the pan – it thickens considerably during baking. Make sure you’re measuring your soup and sour cream correctly (use proper measuring cups, not just eyeballing). If you’re at high altitude, add an extra ¼ cup milk to compensate for faster evaporation. Cover the casserole with foil for the first 20 minutes of baking if your oven runs hot.
Problem: Ham tastes too salty
Some hams are brined more heavily than others, making the final dish salty. Before adding your ham to the recipe, taste a small piece – if it’s very salty, soak the diced ham in cold water for 10 minutes, then drain and pat dry before using. Skip the cream of mushroom soup and make your own white sauce with 3 tablespoons butter, 3 tablespoons flour, and 1½ cups milk plus 1 cup sour cream. Use low-sodium or no-salt-added frozen vegetables, and rinse canned vegetables if you’re substituting those.
Equipment Essentials
- 9×13-inch baking dish (glass or ceramic works best for even heating)
- Large skillet (12-inch for sautéing the ham mixture)
- Large mixing bowl (at least 3-quart capacity for combining ingredients)
- Whisk (for smooth sauce without lumps)
- Cutting board and sharp knife (for dicing ham and vegetables)
- Measuring cups and spoons (for accurate ingredient amounts)
- Box grater (if shredding your own cheese)
- Spatula (for folding and spreading mixture)
Shopping List by Store Section
Dairy Case
- Butter (2 tablespoons)
- Sour cream (1 cup)
- Whole milk (½ cup)
- Sharp cheddar cheese, block (8 oz for shredding)
Freezer Aisle
- Frozen tater tots (1 lb bag)
- Frozen mixed vegetables (2 cups or 10-oz bag)
Canned Goods
- Cream of mushroom soup (1 can, 10.5 oz)
Produce
- Yellow onion (1 medium)
- Fresh garlic (1 bulb)
- Fresh parsley (1 bunch)
Pantry/Spices
- Dijon mustard (check your fridge first)
- Black pepper (check your spice rack)
- Garlic powder (check your spice rack)
- Cooking spray (optional, for pan prep)
Meat Counter
- Leftover cooked ham (1 lb – or use what you already have!)
Success Secrets
1. Layer strategically for the best texture. The order matters: sauce on bottom stays creamy, cheese in the middle melts into pockets of flavor, cheese on top creates a golden crust, and tater tots get crispy edges while absorbing just enough sauce at their bases. Don’t mix it all together or you’ll lose those distinct layers that make each bite interesting.
2. Temperature control prevents disasters. A consistent 375°F is the sweet spot – hot enough to brown the tots and bubble the sauce, but gentle enough that dairy products won’t curdle. Use an oven thermometer to verify your oven’s accuracy because a 25°F difference can mean the gap between perfect and overcooked.
3. Rest time isn’t optional. Those 5 minutes after baking let the sauce thicken and set up so your casserole slices cleanly instead of running all over the plate. Cover loosely with foil during resting to keep everything hot but let steam escape so the tater tots don’t get soggy.
4. Fresh herbs finish the dish. That 2 tablespoons chopped fresh parsley added at the end isn’t just for looks – the bright, fresh flavor cuts through all the richness and makes the whole dish taste more balanced. Dried herbs can’t do the same job here, so don’t substitute.
5. Size your ham pieces consistently. When all your ham cubes are the same ½-inch size, they heat evenly and distribute throughout the casserole uniformly. Random sizes mean some pieces dry out while others stay cold, and you get bites with too much ham next to bites with none at all.
