In a frying pan melt the butter and mash the bread in it until crispy and golden.
On a hot grill place the chicken greased with a drizzle of oil, salt and pepper.
Once the chicken is cooked, place the three slices of bread on the griddle and place the mild Provolone Valpadana PDO on top, let it melt and then move to a cutting board.
Start spreading the mayonnaise on the bread, place two lettuce leaves and three slices of tomato on top, half the chicken breast cut into strips and cover with another slice of bread.
Repeat again and finally cover with the last slice of bread.