Cut the bread in half horizontaly.Spread Ajvar over cut side of each bread half. Sprinkle basil salt and pepper. Top evenly with slice of provolone cheese, tomato slices, and fresh mozzarella cheese. Cover with top half of loaf. Cut filled loaf crosswise into 3 or 4 equal pieces.
Heat the BBQ over medium heat. Coat the BBQ grid with cooking spray. Add sandwiches .Place a cast-iron or other heavy skillet on top of sandwiches; press gently to flatten sandwiches. Cook 3 minutes on each side or until bread is toasted (leave cast-iron skillet on sandwiches while they cook).