Tender herbs, such as basil, parsley and mint, work best for this recipe, but feel free to experiment with hardier ones like rosemary and thyme. Slideshow: More Spring Pasta Recipes
Combine the olive oil, garlic and red pepper flakes in a small skillet. Heat over moderately low heat until fragrant and sizzling, about 2 minutes. Keep warm over low heat.
Meanwhile, cook the spaghetti in a large pot of boiling well-salted water until al dente. Reserve about 1 cup of the pasta cooking water, drain the pasta well and transfer to a large bowl.
Pour the hot garlic oil over the spaghetti, then add the herbs and toss well. Add some of the reserved pasta cooking water to loosen the sauce if needed, and season to taste with salt and pepper.
Serve immediately, with Parmesan cheese on the side.