Bring a large pot of salted water to a boil. Add the linguine and cook until al dente according to package instructions. Drain the pasta and set it aside.
Heat the olive oil in a large skillet over medium-high heat. Once hot, add the chicken in a single layer.
Season the chicken evenly with paprika, garlic salt, salt, and black pepper. Cook for 3 to 4 minutes on one side, or until the first side is golden brown.
Nestle 2 tablespoons of cowboy butter into the skillet. Flip the chicken pieces and continue cooking for another 3 to 4 minutes, or until browned and cooked through to an internal temperature of 165°F.
Remove the chicken from the skillet and place it on a plate. Tent loosely to keep warm.
Reduce the heat to low. Add the remaining cowboy butter, heavy cream, garlic salt, and red pepper flakes to the skillet.
Use a spatula to scrape up the browned bits from the bottom of the pan. Stir gently until the butter melts and the sauce comes together.
Add the cooked linguine and chicken back to the skillet. Toss until the pasta and chicken are coated in the sauce.
Add the lemon juice and stir to combine.
Serve warm, garnished with lemon slices.