Key Takeaways
- Sweet caramelized onions create a rich base without dairy
- Ready in under 45 minutes with just 10 ingredients
- Perfect weeknight dinner for 4 people
- Beginner-friendly steps for creamy, restaurant-quality pasta
Skip the Dairy, Keep the Creaminess
Do you miss creamy pasta since going vegan? Or maybe you’re looking to cut back on dairy without sacrificing comfort food?
This vegan caramelized onion pasta solves that problem.
The secret lies in slowly cooking onions until they transform into sweet, golden flavor bombs. When blended with cashews, they create a sauce so velvety you won’t believe there’s no cream.
Let’s make a plant-based pasta that even dairy lovers will crave.
Nutrition Facts (Per Serving)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 420 | – |
| Total Fat | 14g | 18% |
| Saturated Fat | 2g | 10% |
| Sodium | 380mg | 17% |
| Total Carbs | 65g | 24% |
| Fiber | 5g | 18% |
| Protein | 12g | 24% |
Based on a 2,000 calorie diet
What You’ll Need
Ingredients (Serves 4)
| Ingredient | Amount | Notes |
|---|---|---|
| Yellow onions | 3 large (about 1½ pounds) | Sliced into thin half-moons |
| Raw cashews | 1 cup | Soaked for 4 hours or quick-soaked |
| Pasta (fettuccine or linguine) | 12 ounces | Any pasta works, including gluten-free |
| Olive oil | 3 tablespoons | Divided |
| Garlic | 4 cloves | Minced |
| Fresh thyme | 2 teaspoons | Leaves only, stems removed |
| Nutritional yeast | 3 tablespoons | For cheesy flavor |
| Lemon juice | 2 tablespoons | Freshly squeezed |
| Salt | 1 teaspoon (plus more for pasta water) | To taste |
| Black pepper | ½ teaspoon | Freshly ground |
| Fresh parsley | ¼ cup | Chopped, for garnish |
Kitchen Tools
| Tool | Purpose |
|---|---|
| Large pot | For cooking pasta |
| Large skillet or sauté pan | For caramelizing onions |
| Blender or food processor | For making the sauce |
| Measuring cups and spoons | For precise measurements |
| Sharp knife | For slicing onions and mincing garlic |
| Wooden spoon | For stirring onions |
| Colander | For draining pasta |
| Cutting board | For prep work |
Substitutions
- Cashews: Sunflower seeds work for nut allergies (soak the same way)
- Yellow onions: Sweet onions or shallots (reduce cooking time slightly)
- Fresh thyme: 1 teaspoon dried thyme or 1 tablespoon fresh rosemary
- Nutritional yeast: Omit if unavailable (reduce salt slightly)
- Lemon juice: Apple cider vinegar (use half the amount)
Preparation Time
- Prep time: 15 minutes (plus cashew soaking time)
- Cook time: 30 minutes
- Total time: 45 minutes (plus soaking time)
Step-by-Step Instructions
Preparation Phase
- Soak the cashews
- Take out a medium bowl and measure 1 cup of raw cashews.
- Check the cashews for any debris or bad nuts and discard those.
- For standard soaking: Pour hot (not boiling) water over the cashews until they’re covered by about 1 inch of water.
- Let them soak for at least 4 hours on your counter, or overnight in the refrigerator.
- For quick-soaking: Bring a small pot of water to a boil, turn off the heat, add the cashews, and let them soak for 30 minutes.
- Beginner tip: The longer you soak, the creamier your sauce will be. If you forget to soak ahead of time, the quick-soak method works in a pinch!
- Prep the vegetables
- Place your cutting board on a stable surface.
- Peel 3 large yellow onions by cutting off the top (not the root end), then peeling away the papery outer layers.
- Cut each onion in half from root to tip (top to bottom, not across the middle).
- Place each half flat-side down on your cutting board for stability.
- Slice each half into thin half-moon shapes, about ⅛-inch thick (about the thickness of a quarter coin).
- Beginner tip: Try to keep the slices as even as possible so they cook at the same rate. Don’t worry if they’re not perfect!
- For the garlic, separate 4 cloves from the head.
- Place a clove on the cutting board and place the flat side of your knife on top.
- Gently press down with the heel of your hand to crush the clove, which makes it easier to peel.
- Remove the papery skin and finely chop the garlic into tiny pieces.
- For the thyme, hold the stem at the top and gently pull your fingers down the stem to strip off the leaves.
- Measure about 2 teaspoons of the leaves and set aside.
- Set up your cooking station
- Gather all your prepared ingredients and place them near your stove.
- Have measuring spoons within reach.
- Fill a large pot about ¾ full with water for the pasta (but don’t turn it on yet).
- Place your skillet or sauté pan on the stove ready for the onions.
- Have a wooden spoon or heat-resistant spatula ready for stirring.
- Beginner tip: Having everything ready before you start cooking (mise en place) makes the process much smoother.
Caramelizing the Onions
- Start the caramelization process
- Place your large skillet on the stove and turn the heat to medium.
- Measure and add 2 tablespoons of olive oil to the pan.
- Wait until the oil is shimmering slightly (about 30 seconds to 1 minute).
- Beginner tip: The oil is ready when it easily coats the pan when tilted and looks slightly rippled, but isn’t smoking.
- Carefully add all your sliced onions to the pan (they will fill the pan but will cook down).
- Sprinkle ¼ teaspoon of salt evenly over the onions.
- Using your wooden spoon, gently stir the onions until they’re all coated with oil.
- Spread them out evenly in the pan.
- Cook the onions slowly
- Reduce your stove heat to medium-low.
- Set a timer for 25 minutes.
- Every 3-4 minutes, stir the onions gently with your wooden spoon to prevent sticking and ensure even cooking.
- Beginner tip: This is the most important step! Caramelization is a slow process that can’t be rushed. The onions will gradually change from white to translucent to golden to deep amber.
- After about 10 minutes, you’ll notice the onions beginning to soften and turn translucent.
- After about 15 minutes, they’ll start turning light golden.
- By 20-25 minutes, they should be deeply golden brown and very soft.
- WARNING: If at any point the onions start to stick to the pan or brown too quickly, reduce the heat slightly and add 1-2 tablespoons of water. Use your wooden spoon to scrape up any brown bits from the bottom of the pan – these bits have tons of flavor!
- The onions are done when they’re deeply golden brown, very soft, and sweet-smelling. They should reduce to about ¼ of their original volume.
- Add aromatics
- When onions are fully caramelized, add the minced garlic directly to the pan with the onions.
- Stir constantly for exactly 1 minute. (Set a timer if needed – garlic burns easily!)
- Beginner tip: The garlic should become fragrant but not brown. If it starts to brown, immediately move to the next step.
- Add the thyme leaves to the pan.
- Stir for another 30 seconds to release the thyme’s aroma.
- Turn off the heat completely.
- Beginner tip: Leave the onion mixture in the pan for now. You’ll use some for the sauce and save some for topping.
Making the Sauce
- Prepare the blender
- Drain your soaked cashews using a colander.
- Rinse them under cold water for about 20 seconds.
- Make sure your blender is clean and dry.
- Blend the sauce ingredients
- Using a spoon or measuring cup, transfer about ¾ of the caramelized onion mixture to your blender. (Leave the remaining ¼ in the pan for topping later.)
- Add to the blender:
- The drained and rinsed cashews
- 1½ cups of fresh water (not the soaking water)
- 3 tablespoons nutritional yeast
- 2 tablespoons fresh lemon juice
- ¾ teaspoon salt
- ½ teaspoon black pepper
- Beginner tip: Start blending on low speed for about 10 seconds, then gradually increase to high speed.
- Blend on high speed for 1-2 minutes until completely smooth.
- Stop the blender and check the consistency by rubbing a small amount between your fingers – it should feel completely smooth with no grittiness.
- If it’s not completely smooth, blend for another 30-60 seconds.
- If the sauce seems too thick (it should be pourable but coat the back of a spoon), add more water, 2 tablespoons at a time, and blend briefly until you reach the desired consistency.
- Beginner tip: The sauce will thicken slightly when heated, so it’s better to err on the side of slightly thinner at this stage.
Cooking the Pasta
- Start the pasta water
- Place your large pot of water on the stove.
- Turn the heat to high and cover with a lid to bring it to a boil faster.
- Wait until the water reaches a rolling boil (large bubbles consistently breaking the surface).
- Beginner tip: You can start this step while your onions are caramelizing, about 10 minutes before they’re done.
- Cook the pasta
- Once water is boiling vigorously, add 1 tablespoon salt to the water. (It should taste salty like the ocean.)
- Add 12 ounces of pasta to the boiling water.
- Stir immediately with a wooden spoon or tongs to prevent sticking.
- Set a timer for the exact cooking time listed on the pasta package (usually 8-10 minutes).
- Beginner tip: For this recipe, aim for al dente (still slightly firm when bitten) as the pasta will cook a bit more when combined with the hot sauce.
- Stir the pasta occasionally during cooking to prevent clumping.
- About 2 minutes before the pasta is done, place a heat-safe measuring cup or bowl near your sink.
- When pasta is done, use the measuring cup to scoop out 1 cup of the starchy pasta water before draining.
- Beginner tip: This starchy water is liquid gold! It helps the sauce cling to the pasta and adjust consistency.
- Drain the pasta in a colander but do not rinse it (the starch helps the sauce stick).
Bringing Everything Together
- Heat the sauce
- Return to the skillet with the remaining caramelized onions.
- Place it back on the stove over medium heat.
- Add 1 tablespoon olive oil and stir to coat the onions.
- Carefully pour in all of the blended sauce from the blender.
- Stir gently to combine the sauce with the reserved onions.
- Beginner tip: The sauce may splatter a bit when it hits the hot pan, so pour slowly.
- Combine pasta and sauce
- Add the drained pasta directly to the skillet with the sauce.
- Using tongs or two large spoons, gently toss the pasta to coat it with sauce.
- If the sauce seems too thick, add the reserved pasta water, 2 tablespoons at a time, tossing after each addition until you reach your desired consistency.
- Beginner tip: The sauce will continue to thicken as it cools, so it’s better to have it slightly thinner at this stage.
- Allow everything to heat together for 1-2 minutes, tossing occasionally.
- Turn off the heat.
- Taste a strand of pasta with sauce and add more salt or pepper if needed.
- Serve the pasta
- Use tongs or a pasta server to twirl portions of pasta onto four plates or bowls.
- Spoon any remaining sauce from the pan over each serving.
- Sprinkle each plate with some of the chopped fresh parsley.
- Beginner tip: For a restaurant-style presentation, use tongs to twist the pasta into a tall mound in the center of each plate.
- Serve immediately while hot.
Troubleshooting
| Problem | Solution |
|---|---|
| Onions burning instead of caramelizing | Lower heat immediately and add 1-2 tablespoons of water. Scrape up any brown bits from the pan. For the next batch, use a lower heat setting from the start. |
| Sauce too thick | Add reserved pasta water, 2 tablespoons at a time, tossing after each addition until desired consistency is reached. |
| Sauce too thin | Return the sauce to the pan and simmer gently for 3-5 minutes, stirring constantly, to reduce and thicken. |
| Sauce not smooth | Return to blender and blend longer. If using an older blender, you may need to strain the sauce through a fine-mesh sieve to remove any pieces that didn’t blend fully. |
| Pasta sticking together | Make sure to stir pasta right after adding it to boiling water. If already drained and sticking, toss with a splash of olive oil before adding to sauce. |
| Cashews still gritty after blending | Next time, soak cashews longer. For this batch, try blending again for 2-3 more minutes. If your blender is struggling, try blending in smaller batches. |
| Garlic burned | If you catch it early, remove the pan from heat immediately and transfer the mixture to a cool bowl to stop the cooking. If it’s very burned, you may need to start over as burned garlic will make the whole dish bitter. |
Variations & Substitutions
Make It Gluten-Free
Use your favorite gluten-free pasta. Rice or chickpea pasta work especially well with this creamy sauce.
Add Vegetables
Mix in any of these during the final heating step:
- Sautéed mushrooms (8 oz, sliced and cooked separately until golden)
- Wilted spinach (4 cups fresh, added to hot pasta and stirred until wilted)
- Roasted cherry tomatoes (1 pint, halved and roasted at 400°F for 20 min)
- Steamed broccoli florets (2 cups, cut small and steamed until bright green)
Protein Boost
Add one of these for extra protein:
- Crispy baked tofu cubes (14 oz package, pressed, cubed, and baked at 400°F for 25 min)
- Roasted chickpeas (1 can, drained, dried, and roasted at 400°F for 20 min)
- Sautéed white beans (1 can, drained and warmed in a bit of olive oil)
- Vegan sausage slices (2 links, sliced and pan-fried until golden)
Spice It Up
- Add ¼ teaspoon red pepper flakes with the garlic
- Drizzle with chili oil before serving
- Add a pinch of smoked paprika to the sauce while blending
Storage & Reheating
Refrigerator
- Let pasta cool completely before storing (no more than 2 hours at room temperature)
- Transfer to an airtight container
- Store in refrigerator for up to 3 days
- Sauce will thicken when cold—this is normal
Freezer
- Freeze sauce separately (without pasta) for up to 1 month
- Use freezer-safe containers and leave ½ inch space at top for expansion
- Label with date and contents
- Thaw overnight in refrigerator before using
Reheating
- Stovetop method (best option)
- Place a non-stick skillet over medium-low heat
- Add 2-3 tablespoons water or vegetable broth to the pan
- Add your leftover pasta to the liquid
- Cover with a lid to trap steam
- Heat for about 5 minutes, stirring gently halfway through
- The pasta is ready when it’s heated throughout (test by tasting a piece)
- If it seems dry, add another tablespoon of liquid
- Microwave method
- Place a single serving in a microwave-safe bowl
- Add 1 tablespoon water and stir gently to distribute
- Cover loosely with a microwave-safe lid or damp paper towel
- Heat on 70% power for 2 minutes
- Carefully remove and stir
- If not fully heated, continue heating in 30-second intervals
- Let stand for 1 minute before eating (it continues heating and evens out hot spots)
Safety Notes & Tips
Food Safety
- Always wash hands before handling food
- Refrigerate leftovers within 2 hours of cooking
- Do not leave cashew cream sauce at room temperature for extended periods
- Heat leftovers to at least 165°F (74°C) throughout before serving
Time-Saving Tips
- Caramelize onions in advance and refrigerate for up to 3 days
- Soak cashews overnight in the refrigerator
- Use a food processor to slice onions quickly and uniformly
- Prepare the cashew-onion sauce up to 2 days ahead and store in refrigerator
Cooking Tips
- Caramelizing is a slow process — don’t try to rush by using high heat
- For deeper flavor, add 1 teaspoon balsamic vinegar to onions in the last minute of caramelizing
- Salt the pasta water well — it should taste like the sea
- Reserve more pasta water than you think you’ll need
- For extra creaminess, let the sauce sit in the blender for 1-2 minutes before blending to soften cashews further
Special Diet Notes
- This recipe is:
- Vegan
- Dairy-free
- Egg-free
- Can be made gluten-free with appropriate pasta
- Soy-free
- Contains tree nuts (cashews)
Common Mistakes to Avoid
- Rushing the onions — caramelization takes time, at least 20 minutes
- Not soaking cashews long enough — they won’t blend smoothly
- Overcooking pasta — aim for al dente as it will cook a bit more in the sauce
- Not reserving pasta water — it’s essential for adjusting sauce consistency
- Rinsing the pasta — this removes the starch that helps sauce stick to pasta
- Adding cold pasta to hot sauce — this can make the sauce separate
