Cook the fettuccine pasta according to package directions until al dente; drain and set aside.

While the pasta cooks, season the chicken breasts with salt and pepper.

In a large skillet over medium-high heat, melt 2 tablespoons of butter and cook the chicken for 5-7 minutes per side, or until cooked through.

Remove the chicken from the skillet, let it rest for a few minutes, then slice it into thin strips.

In the same skillet, melt the remaining butter over medium heat; add the minced garlic and sauté for 1 minute until fragrant.

Pour in the heavy cream and bring to a simmer, stirring occasionally.

Reduce the heat to low, gradually whisk in the grated Parmesan cheese until the sauce is smooth and creamy.

Add the cooked fettuccine and sliced chicken to the Alfredo sauce, tossing to coat evenly.

Serve immediately, garnished with extra Parmesan cheese and fresh parsley if desired.