Name: Caramelized Onion Pasta with Chilli Oil
Prep time: 10 min
Cook time: 40 min
Total time: 50 min
Cuisine: Fusion
Ingredients: 12 oz spaghetti or linguine; 3 large yellow onions, thinly sliced; 2 tablespoons olive oil; 2 tablespoons butter; 2 to 3 tablespoons chili oil (adjust to taste); 1 teaspoon salt (or to taste); 2 tablespoons chopped fresh parsley (optional); ¼ cup grated Parmesan (optional)

Sweet, golden caramelized onions tangled with spaghetti and kissed with a drizzle of spicy chili oil—this Caramelized Onion Pasta with Chilli Oil is the weeknight dinner that feels gourmet without the fuss. It’s a beautiful play of rich umami, mellow sweetness, and gentle heat in every forkful.

If you’ve never paired deeply caramelized onions with pasta, prepare for something magical. The onions break down into a jammy consistency that coats the pasta like silk. Add in homemade (or store-bought) chili oil, and you’ve got a dish that dances between comfort and bold flavor.

What Kind of Onions Should I Use?

Yellow onions are your best bet here. They hold up well during the long caramelization process and offer a naturally sweet flavor once broken down. Red onions can work for a sharper edge, while white onions tend to caramelize a bit faster but may lack depth.

For a slightly elevated twist, consider mixing in a shallot or two for a more nuanced flavor.

Ingredients for the Caramelized Onion Pasta with Chilli Oil

Spaghetti or Linguine: The pasta acts as a silky base that embraces the onion’s flavor beautifully.

Yellow Onions: Thinly sliced and slow-cooked until golden and sweet. This is the soul of the dish.

Olive Oil or Butter: For sautéing the onions—butter adds richness, olive oil keeps it lighter. Use both for depth.

Chili Oil: Adds the kick. Homemade chili crisp or your favorite brand will work. Adjust based on spice tolerance.

Salt: Enhances the sweetness of the onions and balances the chili.

Fresh Parsley (optional): A sprinkle adds freshness and color contrast.

Grated Parmesan (optional): For a savory, cheesy finish if you want a more indulgent version.

How To Make the Caramelized Onion Pasta with Chilli Oil

Step 1: Start Caramelizing the Onions

Slice your yellow onions as thinly as possible. In a wide skillet over medium-low heat, add olive oil (or a combo of butter and oil) and your onions. Stir them occasionally for 30–40 minutes. The goal is a deep golden-brown color and jammy texture. Don’t rush this step—it’s where the flavor builds.

Step 2: Cook the Pasta

While your onions are slowly caramelizing, bring a large pot of salted water to a boil. Cook your pasta until just al dente. Reserve about a cup of the pasta water before draining.

Step 3: Combine Pasta and Onions

Once the onions are deeply caramelized, add the drained pasta directly into the skillet. Toss everything together, adding a splash of reserved pasta water to loosen and create a glossy sauce. Let the pasta soak up the onion flavor for a minute or two on low heat.

Step 4: Drizzle with Chili Oil

Turn off the heat and finish with a generous drizzle of chili oil. Stir to distribute the heat evenly throughout the dish. Taste and adjust salt or chili levels as needed.

Step 5: Plate and Serve

Serve immediately with a sprinkle of fresh parsley or a dusting of grated Parmesan, if desired. This pasta is best enjoyed hot and fresh, with the chili oil still glistening on every strand.

Best Ways to Serve and Store Caramelized Onion Pasta with Chilli Oil

This pasta is meant to be served immediately while the chili oil is still warm and fragrant. Pair it with a crisp green salad or roasted veggies for a balanced meal. It also works beautifully as a side to grilled meats or baked chicken.

If you find yourself with leftovers, store them in an airtight container in the fridge for up to 3 days. Reheat gently on the stovetop with a splash of water or more chili oil to revive the sauce. Avoid the microwave if possible, as it can mute the chili flavor.

Frequently Asked Questions

Can I use another type of pasta?

Absolutely! While spaghetti or linguine works well, you can use tagliatelle, fettuccine, or even short pastas like rigatoni. Just be sure to cook it al dente.

Is this dish very spicy?

It can be, depending on the chili oil you use. You control the heat level. Start small and add more to taste.

Can I make this vegan?

Yes! Simply use olive oil instead of butter and skip the Parmesan or use a plant-based alternative.

How long do the onions really take to caramelize?

True caramelization takes time—30 to 40 minutes on low heat. Stir occasionally and don’t rush it. That jammy texture is worth the wait.

Can I make the onions in advance?

Definitely. Caramelized onions keep well in the fridge for up to 5 days. Just warm them before mixing with pasta.

Is chili oil the same as chili crisp?

They’re similar. Chili crisp has more texture with garlic, shallots, or sesame seeds. Use whichever you prefer, or mix both for extra depth.

Want More Pasta Ideas with a Kick?

If you loved this Caramelized Onion Pasta with Chilli Oil, you’re going to be obsessed with these bold, flavorful pasta recipes:

Each one brings its own twist to the table—creamy, tangy, or boldly savory. Perfect for spicing up your weeknight dinner rotation.

📌 Save this recipe to your Pinterest dinner board so you can revisit it when you’re craving something comforting with a spicy kick.

And don’t forget to share your version in the comments. Did you go heavier on the chili oil? Add a protein like chicken or mushrooms?

I love seeing how you make these recipes your own. Questions are welcome too—let’s make pasta night even better, together.

Find more quick & flavorful recipes on my Pinterest: Life with Nina

Caramelized Onion Pasta with Chilli Oil

Author: Nina Johnson
Prep Time: 10 minutes
Cook Time: 40 minutes
Total Time: 50 minutes
Yield: 4 servings 1x
Category: Dinner
Method: Stovetop
Cuisine: Fusion, Italian-inspired
Diet: Vegetarian

Print Recipe

Description

Caramelized Onion Pasta with Chilli Oil is a rich, sweet, and spicy dish that brings gourmet flavors to your table with minimal ingredients. Sweet golden onions melt into a jammy sauce that coats each strand of pasta, while chili oil adds a bold finish. It’s perfect for cozy dinners or a meatless main course with attitude.

Ingredients

Scale

12 oz spaghetti or linguine

3 large yellow onions, thinly sliced

2 tablespoons olive oil

2 tablespoons butter

2 to 3 tablespoons chili oil (adjust to taste)

1 teaspoon salt (or to taste)

2 tablespoons chopped fresh parsley (optional)

¼ cup grated Parmesan (optional)

Instructions

1. Slice the onions very thin. In a large skillet over medium-low heat, add olive oil and butter. Once melted, stir in the onions and cook slowly for 30–40 minutes, stirring occasionally, until deeply golden and jammy.

2. While onions cook, bring a large pot of salted water to a boil. Add pasta and cook until al dente. Reserve 1 cup of pasta water, then drain.

3. Add cooked pasta to the pan with caramelized onions. Toss well, adding reserved pasta water as needed to loosen and create a glossy sauce.

4. Turn off the heat and drizzle chili oil generously over the pasta. Stir to combine. Taste and adjust salt or chili level.

5. Serve hot with optional parsley and grated Parmesan on top.