Bring a large pot of water to a rolling boil. Generously season with salt, then add the fettuccine. Cook the pasta until it reaches al dente texture, usually around 10 minutes or per package instructions. Before draining, reserve ½ cup of the starchy cooking liquid. Drain pasta thoroughly and set aside.

Pat the chicken breasts dry and evenly sprinkle both sides with Italian seasoning, kosher salt, and ground pepper.

Heat olive oil in a large, nonstick skillet over medium-high heat. Once the oil is shimmering, tilt the pan to coat the surface. Lay the chicken into the pan and sear without moving for 5 to 7 minutes until the underside is deeply golden. Turn the chicken over, drop in the butter, and gently swirl the pan to distribute as it melts. Continue cooking for another 5 to 7 minutes, or until the thickest part of the meat reads 165°F internally.

Remove the cooked chicken to a cutting board and let it rest for 3 minutes. Slice crosswise into ½-inch thick pieces. Cover loosely with foil to keep warm while preparing the sauce.

Lower the heat to medium-low and return the same skillet to the stove. Add the butter and pour in the heavy cream, whisking gently until the butter fully dissolves.

Add in the fresh garlic, garlic powder, Italian herbs, salt, and pepper. Whisk continuously until the mixture is smooth and homogenous.

Allow the mixture to simmer gently (do not allow to boil) for 3 to 4 minutes, stirring frequently, until the sauce begins to thicken.

Gradually incorporate the Parmesan cheese, stirring until fully melted and the sauce turns velvety. If the consistency becomes overly thick, introduce a small amount of the reserved pasta water—1 to 2 tablespoons at a time—until desired texture is achieved.

Remove the sauce from the heat and immediately toss in the cooked fettuccine, ensuring the noodles are fully coated.

Distribute the creamy pasta among serving plates. Lay several slices of the warm chicken over each portion. Finish with a sprinkle of fresh parsley, extra Parmesan, and cracked black pepper, if desired.