Season chicken breasts with salt and pepper.
Heat olive oil in a large skillet over medium heat. Cook chicken until golden and cooked through, about 6-7 minutes per side. Remove and slice.
In the same skillet, melt butter and sauté garlic until fragrant.
Pour in heavy cream and bring to a gentle simmer. Stir in Parmesan cheese until smooth and creamy.
Meanwhile, cook fettuccine according to package instructions. Drain.
Add cooked pasta and sliced chicken into the sauce. Toss to combine.
Serve immediately, garnished with chopped parsley if desired.