Caramelized Onion Pasta with Chili Oil wakes the house with a sweet, savory smell and a warm, spicy kick. This simple dish makes weeknights feel special without a lot of fuss. If you like cozy, family-style dinners that come together quickly, you’ll love this one. For another easy family meal with a homey vibe, try our chicken breast with zucchini and squash for an easy side or main to rotate through the week.
Why Make This Recipe
- Quick & Easy: Ready in about 30 minutes from start to finish.
- Family Favorite: Soft, sweet onions and warm chili oil please kids and grown-ups.
- Budget-Friendly: Uses pantry staples and one large onion as the flavor star.
This recipe stands out because the slow-cooked onions turn almost jammy and pair with bright, nutty chili oil. You get sweet, savory, and heat in one bowl. It feels like comfort food — the kind of meal that warms hands and hearts after a busy day.
Ingredients
For the base:
- 12 oz (340 g) spaghetti or bucatini — any long pasta works.
- 2 large yellow onions, thinly sliced (about 4 cups).
- 2 tbsp unsalted butter, softened.
- 1 tbsp olive oil (for sautéing onions).
- Salt and black pepper to taste.
For the chili oil:
- 1/3 cup neutral oil (canola, vegetable, or light olive oil).
- 1–2 tsp red pepper flakes (adjust for heat).
- 2 garlic cloves, smashed and chopped.
To finish:
- 1/2 cup grated Parmesan or Pecorino Romano (optional).
- 1 tbsp lemon juice (brightens the dish).
- Fresh parsley, chopped, for garnish.
- Optional: toasted breadcrumbs or chopped toasted nuts for crunch.
Notes: Use unsalted butter so you can control salt. Grate cheese fresh for the best melt and flavor.
How to Make Caramelized Onion Pasta with Chili Oil
- Start prep: Bring a large pot of salted water to a boil for the pasta. Thinly slice the onions so they cook evenly.
- Tip: Salted water flavors the pasta from the inside out.
- Heat a large skillet over medium-low. Add butter and olive oil. Add the sliced onions and a pinch of salt. Cook slowly, stirring every few minutes.
- Why: Slow cooking (20–25 minutes) lets onions turn golden and sweet without burning.
- After about 10 minutes, lower the heat if onions brown too fast. Add a tiny pinch of sugar if your onions are not sweetening. Continue until onions are deep golden and soft. Season with pepper.
- Mini-tip: Stir more often toward the end so no bits stick and burn.
- While onions cook, make the chili oil: warm the neutral oil in a small saucepan over low heat. Add garlic and red pepper flakes and gently cook for 2–3 minutes until fragrant. Remove from heat and let the flavors infuse.
- Tip: Don’t let the garlic brown — you want aroma, not bitterness.
- Cook pasta until just before al dente (about 1–2 minutes less than package instructions). Reserve 1 cup of the pasta water, then drain.
- Add the drained pasta to the skillet with the caramelized onions. Toss gently over low heat. Add a splash of reserved pasta water to loosen and help the sauce cling. Stir in lemon juice and half the cheese if using.
- Why: Pasta water with its starch helps make a silky coating.
- Drizzle most of the chili oil over the pasta and toss to combine. Taste and add salt, pepper, or more chili oil as desired. Plate and finish with remaining cheese, parsley, and optional crunchy topping.
- Mini-tip: Save a little chili oil for serving so people can add heat to their taste.
How to Serve Caramelized Onion Pasta with Chili Oil
- Serve hot in shallow bowls with a final drizzle of chili oil and a sprinkle of fresh parsley. The oil glints and smells fragrant.
- Add a green salad or roasted vegetables on the side for a full family meal.
- Offer grated cheese and toasted breadcrumbs at the table so everyone can add their favorite texture and salt.
How to Store Caramelized Onion Pasta with Chili Oil
- Fridge: Cool to room temperature, then store in an airtight container for up to 3 days.
- Freezer: Not ideal for long storage (oil and texture change), but freeze if needed in a sealed container for up to 1 month. Thaw in the fridge overnight.
- Reheat: Warm gently in a skillet over low heat with a splash of water or broth to revive the sauce and keep the pasta from drying out. Add fresh chili oil after heating.
Tips to Make Caramelized Onion Pasta with Chili Oil
- Slice onions uniformly so they cook at the same rate.
- Cook onions low and slow — patience builds deep, sweet flavor.
- Use reserved pasta water to make a silky sauce.
- Taste as you go: adjust salt, lemon, and chili oil to balance sweet and spicy.
- Make extra chili oil and store it in the fridge for other dishes.
Variation
- Gluten-free: Swap in your favorite gluten-free pasta and cook according to package instructions.
- Add protein: Toss in cooked shredded chicken or crispy tofu for a fuller meal.
- Herb twist: Stir in basil or thyme instead of parsley for a different herbal note.
FAQs
Can I use other onions?
Yes. Sweet onions or red onions work well. Yellow onions give a nice balance of sweet and savory. Cooking time is similar, but sweetness varies.
How spicy will the dish be?
Spice depends on how much red pepper flakes you use. Start with 1 tsp for mild heat and add more if you like a stronger kick. Offer extra oil at the table.
Can I make the chili oil ahead?
Yes. Make chili oil up to a week ahead and keep it in an airtight jar in the fridge. Bring it to room temperature before using so it pours easily.
What if my onions burn?
If they brown too fast, lower the heat and stir more often. Scrape the pan to release bits, and add a splash of water to deglaze and soften stuck pieces.
Conclusion
This Caramelized Onion Pasta with Chili Oil is a small, cozy bowl of big flavors — sweet, silky onions meet warm, fragrant chili oil. It’s the kind of simple dinner that comforts a tired family and fills the kitchen with an inviting aroma. If you enjoyed this, you might like a nutty topping idea from Why You Should Make Dukkah And How To Do It! which pairs nicely as a crunchy finish. Please leave a comment and a star rating to tell me how it turned out, and share this recipe on Pinterest or Facebook so others can make a warm, spicy weeknight favorite. What twist did you try? Let us know below!
Print
Caramelized Onion Pasta with Chili Oil
- Total Time: 45 minutes
- Yield: 4 servings 1x
- Diet: Vegetarian
Description
A cozy pasta dish featuring caramelized onions and spicy chili oil, perfect for weeknight dinners.
Ingredients
- 12 oz (340 g) spaghetti or bucatini
- 2 large yellow onions, thinly sliced (about 4 cups)
- 2 tbsp unsalted butter, softened
- 1 tbsp olive oil (for sautéing onions)
- Salt and black pepper to taste
- 1/3 cup neutral oil (canola, vegetable, or light olive oil)
- 1–2 tsp red pepper flakes (adjust for heat)
- 2 garlic cloves, smashed and chopped
- 1/2 cup grated Parmesan or Pecorino Romano (optional)
- 1 tbsp lemon juice
- Fresh parsley, chopped, for garnish
- Optional: toasted breadcrumbs or chopped toasted nuts for crunch
Instructions
- Bring a large pot of salted water to a boil for the pasta. Thinly slice the onions.
- Heat a large skillet over medium-low. Add butter and olive oil, then the sliced onions and a pinch of salt. Cook slowly, stirring every few minutes for 20–25 minutes until golden and sweet.
- If onions brown too fast, lower the heat and add a tiny pinch of sugar.
- In a small saucepan, warm the neutral oil over low heat. Add garlic and red pepper flakes, cooking for 2–3 minutes until fragrant.
- Cook the pasta just before al dente. Reserve 1 cup of pasta water, then drain.
- Combine the drained pasta with caramelized onions in the skillet. Toss gently, adding a splash of reserved pasta water, lemon juice, and half the cheese, if using.
- Drizzle most of the chili oil over the pasta and toss to combine, seasoning to taste.
- Serve hot, topped with remaining cheese, parsley, and any optional crunchy topping.
Notes
Use unsalted butter for salt control. Grate cheese fresh for the best melt and flavor.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Main Course
- Method: Baking
- Cuisine: Italian
Nutrition
- Serving Size: 1 serving
- Calories: 350
- Sugar: 5g
- Sodium: 400mg
- Fat: 12g
- Saturated Fat: 4g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 45g
- Fiber: 3g
- Protein: 15g
- Cholesterol: 30mg