01 - Boil the fettuccine or linguine in a large pot of generously salted water until al dente. Reserve approximately 1/2 cup of the pasta cooking water before draining the pasta completely.
02 - While the pasta cooks, heat 2 tablespoons of olive oil in a skillet over medium heat. Add the chopped yellow onion and sauté for about 3 minutes until softened. Then, add the minced garlic and cook for an additional minute until fragrant.
03 - Incorporate the roasted red peppers, chili flakes (if using), and tomato paste into the skillet. Sauté for 2 minutes, stirring to combine.
04 - Pour in the vegetable stock and bring to a simmer. Allow it to cook for 5 minutes. Remove the skillet from the heat.
05 - Transfer the pepper mixture from the skillet to a blender. Add the heavy cream (or plant-based alternative), salt, and black pepper. Blend until a smooth consistency is achieved.
06 - Return the blended sauce to the skillet. Stir in the grated Parmesan cheese, if using. Taste and adjust seasonings as needed.
07 - Add the drained, cooked pasta to the skillet with the red pepper sauce. Toss thoroughly to coat. Add a splash of the reserved pasta water, tablespoon by tablespoon, as needed to achieve a silky sauce consistency.
08 - In a small saucepan, gently heat 3 tablespoons of olive oil over low heat. Stir in the smoked paprika and a pinch of salt. Warm for exactly 1 minute, ensuring the oil does not smoke. Remove from heat immediately.
09 - Plate the pasta, then drizzle generously with the smoked paprika oil. Garnish with fresh basil leaves and additional Parmesan cheese, if desired.