Cook pasta according to package instructions and set aside.
Season diced chicken with salt, pepper, and paprika.
Heat butter in a large skillet over medium heat until melted.
Add chicken and cook for 6–8 minutes until golden and fully cooked.
Stir in garlic, Dijon mustard, lemon juice, red pepper flakes, and dried parsley.
Add cooked pasta to the skillet and toss everything together until coated in the cowboy butter sauce.
Sprinkle parmesan cheese and fresh parsley on top and mix gently.
Serve warm and enjoy the rich buttery flavor.