Bring a large pot of salted water to a boil over high heat. Add the linguine and cook according to package instructions until al dente, usually about 8–10 minutes. Once cooked, drain the pasta, reserving ½ cup of the pasta water, and set it aside to keep warm.

In a medium bowl, whisk together melted unsalted butter, minced garlic, Dijon mustard, Worcestershire sauce, smoked paprika, red pepper flakes, lemon juice, chopped parsley, salt, and black pepper until combined. Set the sauce aside for later.

Heat olive oil in a large skillet over medium heat. Season the boneless, skinless chicken breasts with salt and black pepper, and add them to the skillet. Sauté the chicken for about 5-6 minutes on each side until golden brown and cooked through, reaching an internal temperature of 165°F. Remove the chicken from the pan and let it rest while you prepare the sauce.

In the same skillet used for the chicken, pour in the prepared cowboy butter sauce and bring it to a gentle simmer over medium heat for about 1 minute. Stir in the heavy cream and grated Parmesan cheese until the mixture is smooth and creamy. Allow the sauce to heat through without boiling.

Cut the cooked chicken into bite-sized pieces and return it to the skillet with the creamy sauce. Add the drained linguine and gently toss everything together until the pasta is fully coated with the sauce. Use reserved pasta water to adjust the sauce's consistency if needed.

Plate the Cowboy Butter Chicken Linguine and garnish with additional fresh parsley or basil. Serve hot.