Wash and slice the tomatoes. Drain mozzarella and cut into slices. Heat oil in a pan and fry the beef fillets briefly in it. Season with salt and pepper.
Spread baguette slices with garlic butter. Place two loaves of bread in each ovenproof dish. Place the fillets, tomatoes and mozzarella on top and sprinkle with pepper. Bake under the hot grill of the oven.
Garnish with plenty of basil.