Start by bringing a large pot of salted water to a rolling boil. Once boiling, add the linguine and cook according to package instructions until al dente, usually 9–11 minutes. Reserve ¼ cup of the starchy pasta water before draining.

While the pasta is cooking, season the cubed chicken breast generously with garlic powder, onion powder, paprika, cayenne, salt, and pepper. Let it sit for a few minutes.

In a large skillet, heat olive oil and butter over medium-high heat. Add the seasoned chicken and sear it for 3-4 minutes on each side until golden brown. Keep warm.

Reduce the heat to medium-low and add another tablespoon of butter to the same skillet. Sauté minced garlic for about 30 seconds.

Pour in the chicken broth, lemon juice, and Dijon mustard into the skillet. Simmer for about 2 minutes before whisking in the heavy cream and Parmesan cheese.

Return the chicken to the skillet along with the linguine. Toss to coat evenly, adding reserved pasta water as needed for creaminess.

Stir in fresh parsley and serve immediately, garnished with black pepper and red pepper flakes if desired.