Season the chicken breasts with salt, pepper, and garlic powder. Optional: add paprika for extra flavor.
Heat 2 tablespoons of olive oil in a large skillet over medium heat. Sear the chicken for 6–7 minutes per side until golden and cooked through (165°F internal temperature). Remove and let rest, then slice into strips.
Season shrimp with salt, pepper, and a squeeze of lemon juice. In the same skillet, melt 2 tablespoons of butter and cook shrimp for 2–3 minutes per side, until pink and opaque. Remove and set aside.
Bring a large pot of salted water to a boil. Cook pasta according to package directions until al dente. Reserve 1 cup of pasta water, then drain the pasta.
In the same skillet, melt 2 tablespoons of butter and sauté minced garlic for about 1 minute until fragrant.
Pour in heavy cream and bring to a gentle simmer. Let thicken for 3–5 minutes.
Stir in grated Parmesan cheese until melted and smooth. Add lemon zest and juice, then season with salt and pepper to taste.
If the sauce is too thick, add a splash of reserved pasta water until desired consistency.
Add the drained pasta to the sauce and toss to coat evenly.
Gently stir in the sliced chicken and shrimp until combined and heated through.
Garnish with chopped parsley, extra Parmesan, and red pepper flakes if desired.