Pound out chicken breasts so they are of even thickness. Rub with olive oil, garlic salt & pepper. Lightly grease grill. Place chicken breasts onto hot grill and reduce heat to medium. Cover and cook 5 minutes. Remove lid and flip chicken breasts. Top each piece of chicken with 2 tablespoons marinara each, 1 slice of mozzarella and 2 tablespoons parmesan. Place split kaiser rolls cut side down on grill. Replace lid and cook 1-2 minutes.
Remove kaiser rolls when golden brown. Spread 1 tablespoon butter on each cut side of roll and rub generously with garlic clove, cut side facing the bread.
Remove chicken after another 3-5 minutes or until thoroughly cooked.
Place chicken in between garlic bread bun, top with more cheese, marinara and freshly torn basil, if desired. Serve immediately.