If comfort food had a little attitude, it would be this Onion Pasta with Chili Oil. Sweet, deeply caramelized onions meet a fiery homemade chili oil in a dish that’s equal parts cozy and bold. With garlic, olive oil, and a touch of soy sauce for umami, it’s the perfect balance of sweet, spicy, and savory — the kind of pasta you’ll crave again and again.
Table of Contents
Why You’ll Love This Onion Pasta with Chili Oil
This pasta is proof that a few pantry staples can create magic in under 30 minutes.
- Minimal ingredients, maximum flavor
- Perfectly balanced between sweet and spicy
- Ready in one pan for easy cleanup
- Customizable heat level
- Comforting yet vibrant
- Delicious vegetarian-friendly dinner
When I first made this dish, it started as an experiment — caramelized onions and a drizzle of chili oil over spaghetti. The result was so good I knew it needed a permanent spot in my weeknight rotation. The combo of smoky paprika, garlic, and slow-cooked onions hits every note: rich, spicy, and satisfying.
Ingredients You’ll Need
Every ingredient has a role in building deep, layered flavor.
Main Ingredients
- 12 oz pasta – spaghetti, linguine, or penne work beautifully
- 2 tbsp olive oil – for sautéing the onions
- 1 large yellow onion, thinly sliced – the base of sweet, caramelized flavor
- 3 cloves garlic, minced – adds warmth and aroma
- Salt and pepper, to taste – balances and seasons everything
For the Chili Oil
- 3 tbsp olive oil – rich and fruity base
- 1 tbsp red chili flakes – brings the heat (adjust to preference)
- 1 tsp paprika – adds a smoky depth
- 1 small garlic clove, thinly sliced – infuses the oil
- 1 tsp soy sauce – a touch of umami that enhances the spice
For Garnishing
- Grated Parmesan cheese – creamy, salty contrast
- Fresh basil or parsley, chopped – for a bright herbal finish
- Extra chili flakes – optional, for extra spice
Optional Add-Ons or Substitutes
- Add sautéed mushrooms or spinach for texture
- Swap soy sauce for tamari for gluten-free
- Try Sun-Dried Tomato Pasta for another rich, umami twist
- Replace Parmesan with vegan cheese for a dairy-free version
- Add toasted breadcrumbs for crunch
- Stir in a splash of lemon juice for brightness
Step-by-Step Instructions
This pasta layers deep, slow flavor with just the right amount of heat.
- Cook the pasta:
Bring a large pot of salted water to a boil. Cook pasta until al dente according to package instructions. Reserve ½ cup pasta water before draining. - Caramelize the onions:
In a large skillet, heat 2 tbsp olive oil over medium heat. Add sliced onions and a pinch of salt.
Cook for 15–20 minutes, stirring occasionally, until golden and caramelized. - Add garlic:
Stir in minced garlic and cook for 1–2 minutes, just until fragrant. Season with salt and pepper. (Jake tip: Keep the heat low so the garlic doesn’t burn.) - Make the chili oil:
In a small saucepan, heat 3 tbsp olive oil over low heat. Add red chili flakes, paprika, and sliced garlic.
Let it gently sizzle for 2 minutes — do not burn the garlic. Remove from heat and stir in soy sauce. - Combine everything:
Add cooked pasta to the caramelized onions. Pour in half the chili oil and toss well to coat. Add a splash of pasta water to loosen if needed. - Plate and finish:
Serve hot, drizzling the remaining chili oil over each portion. Top with Parmesan, fresh herbs, and extra chili flakes if desired.
Quick Reminders:
- Cook onions slowly — that’s where the magic happens
- Taste and adjust spice level with chili flakes
- Save some pasta water to create a silky sauce
- Garlic burns fast — keep heat low when infusing oil
- Use freshly grated Parmesan for best texture
Expert Tips for Success
This pasta is simple but rewards patience and precision.
- Use low heat when caramelizing onions — it brings out natural sweetness
- Strain chili oil if you prefer a smoother finish
- Toss pasta directly into the sauce for full flavor absorption
- Add a drizzle of honey for a sweet-spicy contrast
- Want crunch? Sprinkle with toasted panko or nuts
- Pair with Creamy Beef and Shells for a hearty Italian dinner night
Serving Suggestions
This spicy, garlicky pasta shines on its own or as part of a full meal.
- Serve with Garlic Parmesan Dinner Rolls for dipping
- Pair with a crisp salad or roasted vegetables
- Add grilled chicken or shrimp for protein
- Serve as a side with grilled steak or tofu
- Finish with extra chili oil for those who love spice
Storing and Reheating
This dish keeps well and tastes even better the next day.
How to Store It
- Store in an airtight container in the fridge up to 4 days
- Keep leftover chili oil separately for freshness
- Freeze for up to 2 months (reheat gently to preserve texture)
How to Reheat It
- Stovetop: Reheat with a drizzle of olive oil and splash of water over medium-low heat
- Microwave: 45 seconds to 1 minute, stirring halfway through
- Drizzle with leftover chili oil before serving to refresh flavor
Nutrition Information (Per Serving)
- Calories: 450 kcal
- Carbohydrates: 55g
- Protein: 12g
- Fat: 20g
- Saturated Fat: 3g
- Polyunsaturated Fat: 2g
- Monounsaturated Fat: 12g
- Trans Fat: 0g
- Cholesterol: 0mg
- Sodium: 320mg
- Fiber: 4g
- Sugar: 5g
Frequently Asked Questions
Can I make it less spicy?
Yes — reduce chili flakes to ½ tablespoon or skip the extra garnish.
Can I use store-bought chili oil?
Absolutely! Just drizzle to taste after plating.
What pasta works best?
Long noodles like spaghetti, fettuccine, or linguine are ideal for coating in sauce.
Final Thoughts
This Onion Pasta with Chili Oil brings together the sweetness of slow-cooked onions and the heat of homemade chili oil for a dish that’s bold yet comforting. It’s the kind of pasta that keeps you coming back for “just one more bite.”
- Take time with the onions — that’s your flavor foundation
- Adjust spice to your liking with extra chili oil
- Serve hot with herbs and Parmesan for the perfect finish
Onion Pasta with Chili Oil
Ingredients
Equipment
Method
- Bring a large pot of salted water to a boil. Cook pasta until al dente according to package directions. Reserve ½ cup pasta water before draining.
- In a large skillet, heat 2 tbsp olive oil over medium heat. Add sliced onions and a pinch of salt. Cook for 15–20 minutes, stirring occasionally, until deeply caramelized.
- Stir in minced garlic and cook for 1–2 minutes until fragrant. Season with salt and pepper.
- In a small saucepan, heat 3 tbsp olive oil over low heat. Add chili flakes, paprika, and sliced garlic. Let sizzle gently for 2 minutes, then remove from heat and stir in soy sauce.
- Add cooked pasta to the skillet with onions. Pour in half of the chili oil and toss well to coat. Use pasta water as needed to loosen the sauce.
- Serve hot, drizzling remaining chili oil on top. Garnish with Parmesan, fresh herbs, and extra chili flakes if desired.
Nutrition
Notes
- Times estimated from method defaults due to missing explicit durations.
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