Peel, halve and cut onions into thin rings, mozzarella into 1/2 cm slices. Wash sugar snaps and blanch in salted water, strain, rinse and drain. Then cut into 1/2 cm wide strips.
Marinade: Season balsamic vinegar, salt and pepper, mix well with 1 tablespoon mustard and honey. Stir in oil. Mix sugar snaps, onion rings and a little tarragon with the marinade and let stand briefly.
Arrange mozzarella and spread the mariande on it.