Wash the zucchini, peel the potatoes and onions. Roughly grate all the vegetables in a bowl. Add eggs, breadcrumbs, flour, mint and parsley, mix everything well and season with salt and pepper. If the dough is too runny, just add a little more flour or breadcrumbs.
Heat oil in a pan. Pour the batter into the pan one tablespoon at a time and fry the cakes until golden on both sides.