Cook linguine according to package instructions; drain and set aside.

In a bowl, combine the softened butter, minced garlic, lemon juice, lemon zest, parsley, chives, smoked paprika, onion powder, garlic powder, cayenne pepper, salt, and black pepper to make the Cowboy Butter.

In a large skillet, heat olive oil over medium heat, then add diced onion and sauté until softened.

Add diced red and green bell peppers, mushrooms, and garlic to the skillet; sauté until vegetables are tender.

Add the chicken breasts to the skillet and cook until browned and cooked through; remove from the skillet and slice.

Pour in chicken broth and heavy cream, bringing the mixture to a simmer; stir in the Cowboy Butter until melted and well combined.

Toss the cooked linguine with the sauce, sliced chicken, and Parmesan cheese until evenly coated.

Serve hot and garnish with additional parsley if desired.