Rinse zucchini, cut ends into small pieces, cut lengthwise into fine slices. Place on a plate, sprinkle with salt and pepper and rest for about 1/2 hour. Then turn in flour to the other side and roast in batches in enough oil. Place on paper towels to soak up and keep warm.
In the meantime, blanch (scald) the tomatoes, skin, seed, chop and strain. Drain the oil from the frying pan except for 2 or 3 tablespoons. Pour in the tomatoes, season with salt and pepper and cook on a high flame for about 20 minutes.
Heat 2 tbsp of oil in an earthenware dish. Put the zucchini with the tomato sauce and cook briefly on very low heat. Remove from the heat, cover the zucchini with slices of mozzarella, drizzle with a little oil and bake in the oven.
Tip: Zucchini is a type of squash and therefore low in calories, rich in vitamins and easy to digest – just the thing for a light meal!