Wash the asparagus. Peel white asparagus. Cut the woody ends off green and white asparagus. Wash lemon, grate dry and cut off 1 slice. Bring salt water to the boil. Season with lemon slice and sugar.
Let the asparagus peel in it for about 30 minutes at low heat. Then drain. Allow 125 ml stock to cool, bring the remaining stock briefly to the boil again. Cook white asparagus for about 15 minutes, green asparagus for 8-10 minutes.
Wash the schnitzel, knock a little flatter. Season with salt and pepper. Whisk the egg. Turn one after the other in flour, egg and breadcrumbs. Shortly before serving, fry in hot oil while turning for about 5 minutes.
For the sauce, stir the contents of the bag into 125 ml of cooled asparagus stock. Bring to the boil while stirring, switch off the stove. Cut the butter into pieces, fold in well. Refine with 125 ml hot asparagus stock, add peppercorns.
Season with salt and a few squirts of lemon juice. Cut the rest of the lemon into slices. Serve asparagus, cutlets with lemon slices and sauce sprinkled with chervil. Boiled potatoes taste good with it.