Preheat the oven to 180*C/350*F/ gas mark 4. You can either use one large focaccia bread, or smaller focaccia breads. I used 4 focaccia thins, which worked out wonderfully. If you are using the larger one, slice it in half horizontally through the middle with a serrated knife and them cut each half into four so you have 8 square buns. Spread cut sides of the bottoms with Dijon mustard, and the cut sides of the tops with the mayonnaise. Layer the bottoms with salami and ham and sprinkle thickly with the grated cheese. Top with hot peppers, torn green olives and sliced black olives to taste, finally placing the tops of the focaccia over all to form sandwiches. Wrap tightly in foil and then place onto a baking sheet. Bake for 30 to 35 minutes until heated through and the cheese has melted. Serve hot.