Drain the mozzarella. Wash and clean the tomatoes and cut them into 1 cm thick slices. Cut the ciabatta into about 20 slices. Heat the oil in a pan and fry the slices of bread for about 2 minutes, turning them golden.
Set aside for removal. Cut the mozzarella into slices about 5 mm thick. Peel and halve the garlic. Rub garlic into an ovenproof casserole dish (21 x 32 cm; approx. 1 1/2 litres capacity).
Cover the bottom of the casserole dish with half of the slices of bread. Place half of the tomato slices on top. Season with salt and pepper. Place 2 slices of ham on top. Coarsely grate the Parmesan cheese. Spread half of the mozzarella and parmesan on top.
Sprinkle with marjoram. Sprinkle with remaining ciabatta slices. Spread the remaining tomato slices, ham, mozzarella and parmesan on top. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 20-25 minutes.
Wash the marjoram, dab dry and cut into fine strips, except for a little garnish. Sprinkle lasagne with marjoram and garnish.