Heat butter in a large pot over medium-high heat. Season chicken with salt and pepper, then cook until golden brown (about 5 minutes per side). Remove and set aside.
In the same pot, sauté minced garlic for one minute until fragrant.
Add fettuccine, chicken broth, and heavy cream to the pot. Stir well, bring to a gentle boil, then reduce heat and simmer until pasta is al dente (about 10 minutes).
Stir in Parmesan cheese until melted into the sauce.
Slice chicken into bite-sized pieces and return to the pot. Mix well to coat everything in sauce.
Serve hot, garnished with additional Parmesan if desired.
