Place the peeled and deveined shrimp in a bowl. Add lemon pepper, Old Bay seasoning, and paprika. Toss until the shrimp are well coated in spices. Let them sit for a few minutes while you prepare the pasta water.

Bring a large pot of water to a rolling boil. Add the salt (yes, 3–4 tablespoons—this seasons the pasta!) and then add the fettuccine. Cook until just al dente according to package directions. Before draining, reserve 1–2 cups of pasta water, then drain and set aside. Do not rinse the pasta.

In a large skillet, heat 1 tablespoon olive oil and 1 tablespoon of butter over medium heat. Once the butter is foamy, add the seasoned shrimp in a single layer. Cook for 1.5–2 minutes per side until the shrimp are pink and just cooked through. Do not overcook. Remove shrimp from skillet and set aside.

Using the same skillet (do not wipe it clean), reduce the heat to medium-low. Add the remaining 4 tablespoons of butter and let it melt. Stir in the minced garlic and cook for 1–2 minutes, just until fragrant and lightly golden—don’t let it burn.

Add 1 cup of reserved pasta water and the juice of one lemon to the garlic butter. Add a pinch of red pepper flakes for some heat if desired. Stir gently and let it come to a simmer for about 1 minute.

Turn the heat to low. Add the drained fettuccine directly into the sauce (don’t worry if it’s a little wet) along with the grated Parmesan. Toss everything until the cheese melts and the sauce thickens slightly, coating each strand of pasta.

Add the cooked shrimp back into the skillet and toss to combine. Add a splash more pasta water if needed to loosen the sauce. Season with salt and black pepper to taste.

Serve hot, garnished with chopped parsley flakes if desired. Enjoy immediately while the shrimp are tender and the sauce is velvety.