1. Cook the pasta: Boil salted water and cook fettuccine according to package instructions until al dente (8-10 minutes). Drain and set aside.
2. Sauté the chicken: In a skillet over medium heat, melt 2 tablespoons of butter. Season chicken with salt and pepper, cooking until golden brown (6-7 minutes per side) and reaching an internal temperature of 165°F (75°C). Remove from skillet and slice.
3. Prepare the sauce: In the same skillet, melt remaining butter over low heat. Sauté garlic until fragrant (about 1 minute). Stir in heavy cream.
4. Add cheese: Gradually whisk in Parmesan cheese until melted into a creamy sauce.
5. Combine: Toss cooked fettuccine in the sauce until evenly coated. If too thick, add reserved pasta water to achieve desired consistency.
6. Serve: Lay sliced chicken over fettuccine Alfredo and garnish with additional Parmesan if desired.
