Place a slice of gluten free bread on a board and cut into a round.
Then top the bread with the sliced mozzarella. Place the other slice of bread on top to make a sandwich.
Beat the egg in a bowl with a little salt and freshly ground black pepper. Dip the sandwich into the beaten egg.
Heat the olive oil in a pan, add the sandwich and fry for 2-3 minutes on each side, or until golden-brown. Remove from the heat, cut in half and serve on a plate, with chopped tomato basil and olive oil.