Peel the potatoes, wash them and cut into round, fairly thick slices. Peel the tomatoes and remove the seeds. In a bowl, pour in the bread crumbs, grated cheese, a little oregano and the chili pepper in powder. In an oiled earthenware pot, arrange on the bottom a layer of tomatoes cut into minute pieces, salt to taste, and add a layer of potatoes and on top distribute the slices of onion and the bread crumb mixture. Aromatize with basil leaves and dress everything with oil. Repeat the operation with another layer of tomato, one of bread crumbs and add another drizzle of olive oil. Finally, pour in slowly a little water from one side, and bake in a hot oven (425°F) for about an hour, until a golden crust has formed. Serve warm or cold.