Halve the zucchini lengthways and then cut into fine slices. Heat some olive oil in a pan and fry the zucchini slices until golden brown. Add the mint leaves and season with chilli flakes (generously), pepper and a little salt.
Cut the tomatoes and mozzarella into bite-sized pieces and add the cooled zucchini. Mix everything with balsamic vinegar, possibly a little olive oil and, if necessary, season with salt and pepper.