Get your pasta water boiling. Fill your large pot with water—about 4-5 quarts—and bring it to a rolling boil over high heat. Add a generous tablespoon of salt.

While the water comes to a boil, prep your ingredients. Mince the garlic, chop the parsley, squeeze the lemon juice, and pat the shrimp dry with paper towels. Season them with a pinch of salt and pepper.

Drop your linguine or spaghetti into the boiling water and cook according to package directions until al dente, about 8-10 minutes.

About 3 minutes before the pasta is done, melt 2 tablespoons of butter in your large skillet over medium heat. Add the minced garlic and red pepper flakes (if using). Cook for about 30-60 seconds, stirring constantly, until fragrant.

Add the seasoned shrimp to the skillet in a single layer. Cook for 1-2 minutes per side, until they turn pink and opaque. Transfer to a plate and set aside.

Pour in the white wine or chicken broth and scrape up the brown bits from the bottom. Let it bubble and reduce for about 1 minute.

Reduce heat to low. Add the remaining 2 tablespoons of butter and swirl until melted.

Scoop out 1/2 cup of pasta water before draining the pasta. Drain the pasta and transfer directly to the skillet.

Add the cooked shrimp, lemon juice, and half the parsley. Toss with tongs, adding pasta water as needed to create a silky sauce. Taste and adjust seasoning with more salt, pepper, or lemon juice as needed.

Serve immediately, topped with remaining parsley and Parmesan cheese if desired.