Wash the potatoes well, boil in water for about 20 minutes. Wash asparagus, peel and cut off woody ends. Steam in boiling salted water for about 15 minutes
Clean, wash and chop the tomatoes. Mix lemon juice, salt, pepper, sugar and oil. Pour over the asparagus. Peel and rinse the potatoes. Serve with asparagus, tomato, ham and chervil