Bring a large pot of salted water to a boil. Add the fettuccine and cook according to package instructions until al dente. Reserve 1 cup of pasta water, then drain and set aside.

While the pasta is cooking, heat olive oil in a large skillet over medium-high heat. Season the chicken breasts with salt and pepper. Sear the chicken in the skillet for about 6-7 minutes on each side or until thoroughly cooked (internal temperature should reach 165°F). Remove the chicken from the skillet and let it rest before slicing.

In the same skillet, reduce the heat to medium and melt the butter. Add the minced garlic and sauté for about 1 minute until fragrant. Pour in the heavy cream, stirring to combine. Cook for 2-3 minutes until the cream slightly thickens.

Add the grated Parmesan cheese to the sauce, stirring until melted and smooth. If the sauce is too thick, gradually add reserved pasta water until you reach your desired consistency.

Add the drained fettuccine and sliced chicken to the sauce, tossing to coat the noodles evenly. Serve hot, garnished with fresh parsley for a pop of color.