How to make
Boil the potatoes in salted water, remove the water and puree, add 2 tsp salt and 2 tablespoons of olive oil. Add flour and knead a dough.
Parboil the tomatoes, peel the skins, chop them finely and drain through a sieve. Press the garlic, mix it with the tomatoes, add black pepper and oregano. Pour out the oil from the tuna and crush it with a fork, add this to the tomatoes.
Cut the onions into crescents. Preheat the oven to 440°F (225 °C). Grease a tray with oil. Add in the potato dough, form a crust and bake for 20 minutes. Remove from the oven and add the tomato-fish mixture, season, top with thin slices of mozzarella and onions.
Distribute out the cleaned olives, spray with 2 tablespoons of olive oil and sprinkle with grated parmesan cheese.
Bake for 25 minutes. After removing from the oven, sprinkle it with chopped parsley and basil.