Pat the chicken dry and season it with 1 tsp salt and 1/4 tsp black pepper.

Bring 4 qt water and 1/2 tsp salt to a boil in a large pot.

Melt 2 tbsp butter in a large skillet over medium-high heat.

Cook the seasoned chicken in the skillet until golden and cooked through, about 5 to 6 minutes per side.

Transfer the cooked chicken to a cutting board and slice it into strips.

Cook the fettuccine in the boiling salted water until al dente, following the package timing.

Drain the cooked fettuccine in a colander, reserving 1/2 cup of the pasta cooking water.

Melt the remaining 2 tbsp butter in the same skillet over medium heat.

Add the minced garlic and cook until fragrant, about 30 seconds.

Pour the heavy cream into the skillet and bring it to a gentle simmer.

Stir in the Parmesan cheese until melted and the sauce is bubbling and thickened, about 2 to 3 minutes.

Season the Alfredo sauce with the remaining 1/4 tsp black pepper and salt to taste.

Add the drained fettuccine to the Alfredo sauce and toss until evenly coated.

Add a little reserved pasta water if needed and toss until the sauce becomes glossy and coats the pasta.

Fold the sliced chicken into the pasta and heat for 1 minute.

Garnish the Chicken Alfredo with parsley and serve immediately.