Cook potatoes in salted water and pureed, add 2 tsp salt and 2 tbsp olive oil, flour and mix dough. Peel the tomatoes, cut into in small pieces and drain in a sieve. Press the garlic, mix with tomatoes, pepper and oregano. Add crushed with a fork tuna and onion cut in crescents. Potato dough is poured in a buttered baking dish and form boards, and bake in preheated oven for about 20 minutes. Remove and pour tomato-fish mixture, put spices, top rank thin slices mozzarella and onions. Scatter the olives are clean, watered with 2 tbsp olive oil and sprinkle with grated parmesan. Bake 25 minutes. After removing from the oven, sprinkle with chopped parsley and basil.