Cut the loaf of french bread in half and pull out the soft bread in the center. Put the bread chunks in a large bowl and break into small pieces.
Add diced, cooked chicken, alfredo sauce, 1 cup of mozzarella cheese, parmesan cheese, 2 teaspoons minced garlic, and pepper to the bowl with the bread pieces and stir until combined. Microwave the chicken alfredo mixture on high for 3-5 minutes, stirring halfway through.
Scoop the heated chicken alfredo mixture into one of the halves of the French bread loaf, sprinkle with the remaining 1/2 cup of shredded mozzarella cheese and top with the second half of the loaf.
Mix 1 teaspoon minced garlic with the melted butter and brush over the loaf.
Wrap the stuffed bread with Reynolds Wrap Heavy-Duty Aluminum Foil. Bake at 400 degrees for 25-30 minutes until heated through. (For crisper bread, bake uncovered for the last 5 minutes.)
Carefully unwrap the foil, cut the Chicken Alfredo Stuffed French Bread into slices and garnish with chopped parsley, if desired.