Cut chicken into bite-sized pieces and season with salt, pepper, and paprika.
In a bowl, combine softened butter, minced garlic, Dijon mustard, paprika, red pepper flakes (if using), lemon juice, lemon zest, and half of the chopped parsley to create the Cowboy Butter blend.
Heat olive oil in a skillet over medium-high heat and sear chicken until cooked through.
Cook linguine according to package directions; reserve some pasta water before draining.
In the same skillet, deglaze with chicken broth and stir in the Cowboy Butter blend until melted. Add heavy cream and Parmesan cheese until smooth.
Toss in drained linguine and seared chicken; adjust consistency with reserved pasta water if needed. Garnish with remaining parsley.