Prep the basics: Bring a large pot of salted water to a boil. Zest 1 lemon and juice it (about 2–3 tablespoons). Mince 3–4 cloves of garlic. Grate 1 cup Parmesan.

Cook the pasta: Add pasta and cook until al dente. Reserve 1 cup of pasta water, then drain.

Season the chicken: Slice chicken into thin cutlets or bite-size pieces. Pat dry and season generously with salt and pepper.

Sear the chicken: Heat a large skillet over medium-high. Add 1 tablespoon olive oil and 1 tablespoon butter. Cook chicken in an even layer until golden and cooked through, about 4–6 minutes total. Transfer to a plate.

Build the sauce base: Lower heat to medium. Add 2 tablespoons butter to the skillet, then the garlic and a pinch of red pepper flakes. Cook 30 seconds until fragrant, not browned.

Deglaze: Pour in 1/2 cup chicken broth (or white wine). Scrape brown bits from the pan. Simmer 2 minutes to reduce slightly.

Add lemon: Stir in lemon zest and juice. Taste and adjust salt and pepper.

Emulsify: Add the drained pasta and chicken to the skillet. Toss with a splash of reserved pasta water and 2 more tablespoons butter until the sauce turns glossy and clings to the noodles.

Finish: Sprinkle in most of the Parmesan and chopped parsley. Toss again, adding more pasta water as needed for a silky sauce.

Serve: Top with remaining Parmesan, extra lemon zest, and a drizzle of good olive oil. Serve immediately.