1) Rinse i beans, drain and mash them. Clean and grate the zucchini and join them to beans. Also join the egg and the yolk, the chopped mint, parmesan, turmeric, breadcrumbs, salt and pepper. Mix everything, adding more breadcrumbs if the mix is ​​too soft. With wet hands, train 4 hamburgers.

2) Make the sauce: mix it yogurt, 2 tablespoons of lemon juice, a little bit of chopped mint, salt and pepper and a couple of tablespoons of water. Let it rest in the fridge. Wash i tomatoes, dry them and cut them into thick slices. Cut the sandwiches in half.

3) Heat 1/2 finger of oil in a large non-stick pan; brown the hamburgers over low heat for 4 minutes on each side until golden, drain on kitchen paper and add salt. Briefly brown the cut side sandwiches in oil. Spread the bases with a little Yogurt Based Sauce and stuff them with the tomato slices, the hamburgers, the remaining sauce and some salad leaf.