Clean the salad, wash it, cut it in half and cut out the stalk. Cut salad into bite-sized pieces. Drain mozzarella. Clean, wash, halve and slice the radishes
Peel onion, dice finely, mix with vinegar and mustard, season with salt, pepper and sugar. fold in the oil
Drain the tuna. Mix salad, radishes, mozzarella, tuna and vinaigrette, season again and arrange in small bowls. Bread tastes good with it