In a small saucepan, heat ¼ cup of high-quality olive oil over medium heat. Once the oil is warm, add 2 minced garlic cloves and 1 teaspoon of chili flakes. Sauté for 2–3 minutes until fragrant and golden. Remove from heat and let flavors infuse as oil cools.

In a large skillet, warm 2 tablespoons of olive oil over medium-low heat. Add 2 sliced yellow onions and a pinch of salt, stirring to combine. Cook for about 20 minutes until soft and golden brown.

Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions, typically around 8–10 minutes for al dente. Reserve 1 cup of the pasta cooking water before draining.

Once the onions are caramelized, add the minced garlic from the chili oil to the skillet. Cook for an additional 1–2 minutes until fragrant. Add the drained pasta, tossing to coat well with the onions and reserved pasta water until smooth.

Drizzle the prepared chili oil over the pasta and toss to combine thoroughly. Adjust seasoning as needed and serve hot, garnished with extra chili oil.