Cut the chicken breast into even bite-sized cubes for uniform cooking. Fill a large pot with water, add a pinch of salt, and bring it to a boil for the linguine.

Add the linguine to the boiling water and cook according to the package instructions, typically for about 10 minutes, until al dente. Reserve ¼ cup of pasta water before draining.

Season chicken cubes with garlic powder, onion powder, smoked paprika, cayenne pepper, salt, and pepper. Heat olive oil in a skillet, add chicken, and cook for 6–8 minutes until golden brown.

In the same skillet, add butter and let it melt. Toss in minced garlic, sauté for about a minute. Add chicken broth, deglaze the pan, then stir in heavy cream and Dijon mustard. Simmer for 2–3 minutes.

Add remaining butter, shredded Parmesan cheese, lemon juice, and red pepper flakes to complete the sauce. Adjust consistency with reserved pasta water.

Return chicken to the skillet, add drained linguine, and toss until well-coated in the sauce.

Plate hot, garnished with fresh parsley and optional extra Parmesan cheese or lemon slices.