Drain the corn on a sieve. Wash the tomatoes, remove the stalks. Cut tomatoes into quarters, remove seeds and dice the flesh. Clean, wash and drain lettuce. Wash the chives and cut into fine rolls, except for a little garnish.
Mix vinegar, salt, pepper and sugar and add oil. Stir in the tomatoes and chive rolls. Arrange salad leaves and corn on plates. Pour some marinade over it and garnish with chives.