Boil the pasta: Bring a large pot of salted water to a rolling boil. Add the pasta and cook until just shy of al dente. Reserve at least 1/2 cup of the starchy cooking water before draining.

Prep the shrimp: Pat shrimp dry with paper towels. Season with a big pinch of salt and a few grinds of pepper. Dry shrimp sear better and stay juicy.

Heat the pan: In a large skillet over medium-high heat, warm 1 tablespoon olive oil and 1 tablespoon butter until the butter foams.

Sear the shrimp: Add shrimp in a single layer. Cook 1–2 minutes per side, just until opaque and lightly pink. Remove to a plate. Do this in batches if needed to avoid crowding.

Build the sauce: Lower heat to medium. Add remaining olive oil and butter. Stir in garlic and red pepper flakes. Cook 30–60 seconds, until fragrant but not browned.

Deglaze (optional but great): If using wine, pour it in and simmer 30–60 seconds, scraping up any browned bits. Let it reduce by about half.

Add lemon: Stir in lemon zest and juice. Taste and season with salt and pepper. The sauce should be bright, buttery, and well balanced.

Toss with pasta: Add drained pasta to the skillet with a splash of reserved cooking water. Toss until the sauce lightly coats the noodles and turns glossy. Add more pasta water as needed to loosen.

Finish with shrimp and parsley: Return shrimp to the pan and toss just to warm through, 30 seconds. Sprinkle in parsley. Taste and adjust salt, pepper, and lemon.

Serve: Plate immediately. Top with extra parsley, a drizzle of olive oil, and grated Parmesan if you like.