Preheat your oven to 375°F (190°C).
In a mixing bowl, combine the shredded chicken and Alfredo sauce. Mix well until the chicken is evenly coated.
Slice the French bread loaves in half lengthwise and place them on a baking sheet, cut side up.
In a small bowl, mix the softened butter, minced garlic, Italian seasoning, red pepper flakes, salt, and pepper. Spread this garlic butter mixture evenly over the cut sides of the bread.
Spoon the chicken and Alfredo mixture onto each half of the bread, spreading it out evenly.
Top each half with shredded mozzarella and grated Parmesan cheese.
Bake in the preheated oven for 15-20 minutes, or until the cheese is melted and bubbly, and the edges of the bread are golden brown.
Remove from the oven and let cool for a few minutes. Garnish with chopped parsley before slicing and serving.