Peel and finely chop the onion. Peel red onion and cut into fine rings. Wash parsley, dab dry and chop finely. Chop nuts coarsely. Cut cheese into slices. Mix vinegar, onion, parsley, salt, pepper and sugar.
Whip oil into the mixture. Place cheese in the vinaigrette. Clean and wash the salad, pluck into bite-sized pieces and drain on a sieve. Arrange some lettuce leaves, onion rings and cheese wedges with some vinaigrette on four plates. Serve sprinkled with nuts. Served with baguette