Caramelized Onion Pasta with Chilli Oil

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Rich, silky, and packed with umami, this Caramelized Onion Pasta with Chilli Oil is a game-changer in the world of quick yet gourmet dinners. It combines deeply golden onions with a kick of spicy oil, perfectly coating each strand of pasta. The balance between the mellow sweetness of the onions and the fiery heat of the chili oil creates a comforting yet bold dish that’s irresistibly crave-worthy.

This pasta is proof that simple ingredients can lead to stunning results. With minimal prep and maximum flavor, it’s the kind of dish that turns a regular weeknight into something special. Whether you’re cooking for yourself, impressing a guest, or just looking for a new favorite comfort food, this recipe delivers.

Why You’ll Love This Caramelized Onion Pasta with Chilli Oil

• Combines sweet, spicy, and savory flavors beautifully.
• Uses pantry staples to create a rich and satisfying meal.
• Ready in under 30 minutes.
• Perfect for vegetarians and can be easily made vegan.
• Elegant enough for a dinner party, simple enough for a Tuesday night.

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Preparation Phase & Tools to Use

Before diving into cooking, gather your essentials. You’ll need:

• Large skillet or sauté pan – Crucial for caramelizing the onions evenly without burning.
• Pasta pot – For boiling your pasta to al dente perfection.
• Tongs or pasta fork – For transferring pasta directly into the sauce.
• Wooden spoon or spatula – Helps stir onions without breaking them up too much.
• Microplane or grater – Optional, for finishing with a fresh shower of cheese.

Each of these tools ensures even cooking and keeps the process efficient, especially during the quick assembly when the pasta meets the sauce.

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Preparation Tips

Start caramelizing your onions first—they take time, and patience is key. Don’t rush the process; low and slow heat brings out their natural sweetness. Use a wide pan to spread the onions out evenly, which helps them brown rather than steam. When making the chili oil, keep a close eye on the garlic and chili flakes—infuse them in oil gently without letting them burn. Lastly, always save a bit of pasta water to emulsify the sauce. It binds everything together and adds a silky finish.

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Ingredients for this Caramelized Onion Pasta with Chilli Oil

• 12 oz (340 g) spaghetti or bucatini
• 2 large yellow onions, thinly sliced
• 4 tbsp olive oil (divided)
• 2 tbsp unsalted butter
• 1 tsp salt
• 1/2 tsp sugar (optional, to speed up caramelizing)
• 1/2 cup reserved pasta water
• 1/4 cup grated Parmesan (optional)
• Fresh chopped parsley, for garnish

For the Chilli Oil:

• 1/3 cup olive oil
• 4 cloves garlic, thinly sliced
• 1.5 tsp red pepper flakes (adjust to taste)
• 1/2 tsp smoked paprika (optional for depth)
• Pinch of salt

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Step 1: Start Caramelizing the Onions

In a large skillet over medium-low heat, warm 2 tablespoons of olive oil and the butter. Add the thinly sliced onions and a pinch of salt. Cook, stirring occasionally, for about 25–30 minutes until the onions are deep golden brown and soft. Add a pinch of sugar halfway through to speed up the caramelization if desired.

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Step 2: Prepare the Chilli Oil

While the onions cook, make the chili oil. In a small saucepan, heat 1/3 cup olive oil over low heat. Add garlic slices and let them sizzle gently for 2–3 minutes until golden and fragrant (not brown). Add the red pepper flakes, smoked paprika, and a pinch of salt. Stir and remove from heat. Set aside to infuse.

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Step 3: Cook the Pasta

Bring a large pot of salted water to a boil. Add the pasta and cook until just al dente according to package directions. Before draining, reserve at least 1/2 cup of the pasta water.

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Step 4: Combine Pasta with Onions

Once the pasta is cooked and drained, add it directly into the skillet with the caramelized onions. Toss gently to combine and coat the noodles with the onion mixture. Add splashes of pasta water as needed to loosen and create a sauce-like consistency.

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Step 5: Add the Chilli Oil

Pour the infused chili oil over the pasta mixture and toss again. Taste and adjust for seasoning. You can control the heat here — use all or just some of the chili oil depending on your spice preference.

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Step 6: Garnish and Serve

Finish with a sprinkle of grated Parmesan if using, and freshly chopped parsley for brightness. Serve hot and enjoy immediately for the best flavor and texture.

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Notes

Caramelized Onion Pasta with Chilli Oil is all about timing and layering flavors. The longer the onions cook, the sweeter and more complex they become, so don’t rush them. Using high-quality olive oil and fresh garlic makes a big difference in the chili oil’s flavor profile. Feel free to use gluten-free pasta or whole wheat noodles for a healthier twist. If you’re vegan, skip the Parmesan or use a dairy-free alternative.

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Watch Out for These Mistakes While Cooking

• Rushing the onions: Caramelizing takes time. Turning the heat up too high will burn them instead of browning them slowly.
• Overcooking the garlic in chili oil: Garlic burns quickly. Once golden, remove it from heat to avoid bitterness.
• Forgetting to save pasta water: This starchy water helps bind the sauce to the pasta. Always save some before draining.
• Using too much chili oil: Add gradually. You can always add more heat, but you can’t take it out.
• Skipping the salt: Every layer—from pasta water to onions to chili oil—needs seasoning to enhance overall taste.

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Storage Instructions

Let the pasta cool to room temperature before storing. Transfer to an airtight container and refrigerate for up to 4 days. To reheat, add a splash of water or olive oil to a pan and gently warm the pasta over low heat until hot. This dish is not ideal for freezing due to texture changes in the onions and pasta.

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Estimated Nutrition

Per serving (based on 4 servings total):

• Calories: ~480
• Protein: 10g
• Carbohydrates: 55g
• Fat: 24g
• Saturated Fat: 5g
• Fiber: 4g
• Sugar: 5g
• Sodium: 290mg

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Frequently Asked Questions

What kind of pasta works best?

Spaghetti, linguine, or bucatini work great because they hold the sauce well. But feel free to try it with any pasta you have on hand.

Can I make it less spicy?

Yes! Just use half the amount of red pepper flakes or remove the chili oil from the final step.

Is this dish vegan?

It can be! Just omit the Parmesan or replace it with a plant-based cheese.

How do I get perfect caramelized onions?

Low and slow is the key. Cook on medium-low heat and stir occasionally for 25–30 minutes until deeply golden.

Can I add protein to this dish?

Absolutely. Add sautéed mushrooms, grilled chicken, or crispy tofu for extra protein.

Can I use store-bought chili oil?

You can, but homemade chili oil has a fresher, more customizable flavor. Still, a quality store-bought option works in a pinch.

What’s a good garnish besides parsley?

Try fresh basil, a squeeze of lemon, or a light dusting of lemon zest for brightness.

How spicy is this pasta?

It’s moderately spicy, but you can control the heat entirely based on how much chili oil you use.

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Conclusion

Caramelized Onion Pasta with Chilli Oil is the ultimate marriage of simplicity and depth. It turns humble pantry ingredients into a luxurious, flavor-packed meal in under 30 minutes. Whether you’re looking for a weeknight dinner idea or a meatless main course with flair, this dish delivers bold taste with minimal fuss. Try it once, and it’ll quickly become a go-to favorite in your recipe rotation.

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