In a large pot, bring salted water to a boil. Add the linguine or spaghetti and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water, then drain and set aside.
In a large skillet over medium heat, add the olive oil. Once hot, add the minced garlic and red pepper flakes (if using). Sauté for about 1-2 minutes until the garlic is fragrant but not browned.
Add the shrimp to the skillet, seasoning with salt and pepper. Cook for about 2-3 minutes on each side, or until the shrimp turn pink and opaque.
Once the shrimp are cooked, pour in the lemon juice and lemon zest. Stir to combine, allowing the flavors to meld for another minute.
Add the cooked pasta to the shrimp mixture in the skillet. Toss well to coat the pasta in the sauce, adding reserved pasta water a little at a time if needed to loosen the sauce.
Remove from heat and stir in the chopped parsley. Taste and adjust seasoning, if needed. Serve immediately, topped with grated Parmesan cheese.
Notes
Serve the pasta in large bowls, topped with extra parsley and lemon slices for an attractive finish.