Add the softened butter to a medium mixing bowl and use a spoon to stir together the butter, garlic, 1 teaspoon of parsley, chives and basil until thoroughly combined.
Evenly spread over both halves of the bread loaf. Arrange tomatoes in an even single layer over each half of the bread and season with salt and pepper. Top with the mozzarella and Parmesan cheese.
Bake until the cheese has melted and the edges are golden brown, about 20 minutes.