Season the chicken slices with salt and pepper. Heat olive oil in a large skillet over medium heat, then add the chicken. Cook until golden brown on both sides, about 5-7 minutes per side. Remove from the skillet and set aside.

In a large pot, bring water to a boil and cook the fettuccine according to package instructions until al dente. Drain and set aside.

In the same skillet used for the chicken, melt butter and add minced garlic. Sauté until fragrant, about 1 minute. Pour in the heavy cream, bringing it to a gentle simmer. Stir in the Parmesan cheese, allowing it to melt smoothly into the sauce. Adjust seasoning with salt and pepper to taste.

Add the cooked fettuccine to the skillet with the sauce. Toss to coat each strand with the creamy mixture. Slice the cooked chicken and arrange it over the pasta before serving.

Garnish with chopped parsley and additional Parmesan cheese if desired. Serve immediately with your choice of side.

Transfer any leftovers to an airtight container and refrigerate for up to 3 days. Reheat gently on the stove with a splash of cream or milk to restore the sauce's creaminess.