Cut the bread slices into 8 pieces and put them into an oven-safe pan sized 20/30 cm. Put the dices of cheese and ham in between.
Scramble the eggs and add the milk and the two types of mustard in a bowl. Season with salt and black pepper and stir well. Pour this mixture over the bread and let it rest for at least 3 hours. You can occasionally stir carefully in order to soak the bread evenly. Put cherry tomatoes over the dish before putting it into the oven.
Bake for about 20 min. in a preheated oven to 200 °С or until golden.