Begin by bringing a large pot of salted water to a rolling boil over high heat. Add your choice of pasta, stirring occasionally. Cook until al dente, about 8-10 minutes, then reserve ½ cup of pasta water before draining.

In a large skillet, melt butter over medium heat. Season chicken breasts with salt, pepper, and paprika, then add to the skillet. Sear for 5-7 minutes on each side until cooked through. Remove and let rest.

In the same skillet, melt remaining butter. Add minced garlic and sauté for about 1 minute until fragrant.

Stir in Dijon mustard, lemon juice, and zest, followed by red pepper flakes and dried thyme. Cook for another minute until flavors combine.

If desired, add heavy cream and let the sauce simmer for 2-3 minutes until it thickens slightly.

Return the cooked chicken to the skillet, adding the drained pasta. Toss everything together for 1-2 minutes, adding reserved pasta water if needed.

Remove from heat and stir in grated Parmesan cheese and parsley. Serve hot.