Meanwhile, shave asparagus using a vegetable peeler into long thin strips. When peeling, you will get to a part where you can’t peel anymore strips from the asparagus. At that point, snap the tender asparagus tips off to use in the pasta. The rest of the asparagus can be saved for a later use in an omelet, scrambled eggs, a salad, etc.
Once water is boiling, season heavily with salt. Drop in pasta and stir.
While pasta cooks, heat a large skillet over medium heat. Add in garlic and cook until lightly golden. Stir in pepper flakes.
Add a ladle or two of pasta water to the pan to prevent garlic from overcooking and to being creating a sauce.
Once pasta is al dente, add to the skillet with the garlic. Stir to coat and immediately add in the shaved asparagus (tops included).
Add in a dash more pasta water if necessary and toss everything coat. The heat of the pasta will wilt/cook the asparagus.
Add in lemon juice, parsley and season to taste with salt. Finish with more olive oil if desired.