Wash and peel the asparagus and cut off the woody ends. Cook the asparagus in boiling salted water for 12-15 minutes. In the meantime wash, clean and halve the tomatoes. Clean the mushrooms and cut into thin slices. Mix vinegar, salt, pepper and sugar.
Whip the oil into it. Arrange asparagus, tomatoes, mushrooms and olives on 4 small plates. Spread the vinaigrette evenly over them. Sprinkle with pepper and serve garnished with chervil as desired