Introduction

Caramelized Onion Pasta with Chili Oil is a comforting and flavorful dish that beautifully balances sweet, savory, and spicy notes. The luscious caramelized onions and fragrant chili oil coat each noodle, creating a simple yet impressive meal perfect for any night.

A close-up view of a single layer of cooked thin pasta noodles coated in a glossy, light brown sauce, topped with small pieces of dark red chili flakes and flecks of black pepper, scattered bits of finely chopped green herbs, and tiny white sesame seeds, all sitting in a shallow white bowl, against a white marbled texture background. photo taken with an iphone --ar 4:5 --v 7

Ingredients

12 oz pasta (spaghetti, penne, or linguine)
2 tablespoons olive oil (for sautéing)
1 large yellow onion, thinly sliced
3 cloves garlic, minced
Salt and pepper, to taste
3 tablespoons olive oil (for chili oil)
1 tablespoon red chili flakes
1 teaspoon paprika
1 small garlic clove, thinly sliced
1 teaspoon soy sauce
Grated Parmesan cheese, for garnish
Fresh basil or parsley, chopped, for garnish
Extra chili flakes (optional)

Instructions

Step 1: Thinly slice the onion into even rings. Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the onions with a pinch of salt and sauté, stirring occasionally, for 25-30 minutes until golden and soft.
Step 2: About 5 minutes before the onions are done, add the minced garlic and cook until fragrant, stirring frequently. Season the onions with salt and pepper, then set aside.
Step 3: In a small saucepan, warm 3 tablespoons of olive oil over medium heat. Add the thinly sliced garlic and sauté for 1-2 minutes until fragrant but not browned.
Step 4: Stir in the red chili flakes and paprika. Cook for 2-3 minutes to infuse the oil with spices.
Step 5: Add 1 teaspoon of soy sauce, stir well, and simmer for 2 more minutes. Remove from heat and set aside.
Step 6: Meanwhile, bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Reserve 1 cup of pasta water before draining.
Step 7: Combine the cooked pasta with the caramelized onions in a large bowl or pan. Toss well to coat the noodles evenly.
Step 8: Drizzle the chili oil over the pasta and toss to combine. Add reserved pasta water a little at a time if the pasta seems dry to loosen the sauce.
Step 9: Garnish with grated Parmesan cheese and chopped fresh basil or parsley. Sprinkle extra chili flakes if desired.
Step 10: Serve immediately while hot, either on its own or with a side salad.

Tips & Variations

Use long pasta like spaghetti or linguine to better catch the caramelized onions and chili oil.
Adjust the red chili flakes to suit your heat preference, or substitute with fresh chili slices for a different texture.
Adding a splash of pasta water helps achieve a silky sauce that clings beautifully to the noodles.
For a vegan version, skip the Parmesan or substitute with a plant-based cheese or nutritional yeast.

Storage

Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in a skillet over low heat, adding a splash of water or olive oil to restore the sauce’s texture. This dish is best enjoyed fresh but still delicious when reheated carefully.

How to Serve

A close-up of a plate of spaghetti shows a single layer of glossy noodles coated in a light brown sauce. The pasta is topped with small dark brown crispy chili flakes scattered across, along with tiny green parsley bits. A fine dusting of grated cheese and black pepper is spread evenly on top, adding texture and contrast. The dish is served in a white bowl, set against a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use pre-made chili oil instead of making it from scratch?

Yes, pre-made chili oil can be used for convenience. However, making it fresh allows you to control the flavors and adjust the heat to your liking.

What type of pasta works best for this recipe?

Long pasta shapes like spaghetti or linguine work best as they catch the caramelized onions and chili oil more effectively, but penne or other shapes can also be used based on your preference.