Clean and wash the zucchini and cut them into very thin slices lengthwise. Cut the cheese into sticks. Finely dice ham. Clean, wash and drain lamb's lettuce well on a sieve.
Peel onion and chop very finely. Wash parsley, dab dry and chop finely. Mix vinegar, salt, pepper, sugar, parsley and onion. Whip the oil into it. Mix lamb's lettuce, zucchini and cheese.
Spread vinaigrette over it. Arrange on four plates. Sprinkle diced ham on top.