Prep the Chicken
In a medium bowl, season sliced chicken breasts with smoked paprika, garlic powder, onion powder, red pepper flakes, salt, and pepper. Toss to coat evenly.

Sear the Chicken
Heat 1 tbsp olive oil in a large skillet over medium-high heat. Add chicken and sear for 5–6 minutes per side until golden brown and cooked through. Remove from skillet and set aside.

Cook the Pasta
In a large pot of salted boiling water, cook linguine until al dente according to package instructions. Reserve 1 cup of the pasta water before draining.

Make the Cowboy Butter Sauce
In the same skillet, reduce heat to medium and melt butter. Add minced garlic and sauté for 1 minute until fragrant. Stir in Dijon mustard and lemon juice, then pour in heavy cream (if using) and whisk until slightly thickened, about 2 minutes.

Combine Pasta and Sauce
Add cooked linguine to the skillet. Toss well to coat with sauce, adding reserved pasta water a little at a time for consistency. Stir in Parmesan cheese.

Finish the Dish
Return chicken to the skillet. Toss everything together for 1–2 minutes until well combined and heated through.

Garnish and Serve
Sprinkle with chopped parsley and extra red pepper flakes if desired. Serve hot with lemon wedges or garlic bread.