In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the thinly sliced yellow onion along with a pinch of salt. Sauté for about 25-30 minutes, stirring every 5-7 minutes. You'll know they're done when the onions are soft, golden brown, and fragrant. At the 25-minute mark, add 3 minced garlic cloves to infuse the mixture with flavor right before finishing.

In a small saucepan, warm 3 tablespoons of olive oil over low heat. Once heated, add 1 small sliced garlic clove and cook for 1-2 minutes until fragrant. Next, stir in 1 tablespoon of red chili flakes and 1 teaspoon of paprika. Allow the mixture to infuse for about 2-3 minutes, stirring gently. Finally, add 1 teaspoon of soy sauce and let it simmer for another 2 minutes before removing from heat.

Bring a large pot of salted water to a rolling boil. Add 12 oz of your preferred pasta, cooking it according to package instructions until al dente—usually around 8-12 minutes. Just before draining, reserve 1 cup of the starchy pasta water to help create a smoother sauce. Drain the pasta well, ensuring it retains some heat as you combine it with the onions.

Return the drained pasta to the pot and add the caramelized onions along with the oil from the skillet. Drizzle in the prepared chili oil for a spicy kick. Toss the pasta gently to combine, ensuring each piece is coated. If needed, add some reserved pasta water a little at a time to achieve your desired sauce consistency.

Plate the Caramelized Onion Pasta and generously top it with grated Parmesan cheese for creaminess. Finish with freshly chopped basil or parsley to add a pop of color and aroma. Optionally, sprinkle extra chili flakes over the dish for added heat. Serve hot.