Peel and finely chop the onion. Cut ham into small cubes. Wash parsley, cut into fine strips. Mix cream cheese, mayonnaise, ham, onion and half of the parsley.
Cut baguette into 8 slices. Coat 4 slices with 1/4 of the cream cheese mixture each. Place 1 slice of baguette on each slice. Fasten with a small wooden skewer. Wash the salad leaves and pluck into bite-sized pieces.
Clean, wash and slice the mushrooms. Whip vinegar and oil. Season with salt, pepper and sugar. Mix salad, mushrooms, remaining parsley and marinade. Arrange in portions with 1 baguette bite each.