Wash and peel the asparagus and cut off the woody ends. Cook in boiling salted water with 1 pinch of sugar for about 15 minutes. In the meantime, clean and slice the mushrooms. Peel and finely chop the onion. Finely dice the salmon ham. Wash chives, shake dry, put some stalks aside for garnishing.
Cut the rest of the chives into small rolls. Heat the oil in a pan, fry the mushrooms in it while turning, remove. Add onion and fry until transparent, remove. Put the salmon ham in the pan and fry briefly while turning. Put onion and mushrooms back into the frying fat. Heat, deglaze with vinegar, bring to the boil briefly and season with salt, pepper and sugar. Stir cream balance and starch until smooth. Lift asparagus out of the asparagus water, drain and keep warm. Measure out 1/4 litre of asparagus water, bring to the boil, stir in the mixed starch and bring to the boil again. Season to taste with salt, pepper, lemon peel and lemon juice. Stir 2-3 tablespoons of the sauce drop by drop into the egg yolk. Then stir and let it run into the sauce.
Stir cream balance and starch until smooth. Lift asparagus out of the asparagus water, drain and keep warm. Measure out 1/4 litre of asparagus water, bring to the boil, stir in the mixed starch and bring to the boil again. Season to taste with salt, pepper, lemon peel and lemon juice. Stir 2-3 tablespoons of the sauce drop by drop into the egg yolk. Then stir and let it run into the sauce. Arrange the asparagus with mushroom vinaigrette, chives and lemon wedges on a plate. Add the rest of the vinaigrette and lemon sauce garnished with chervil in small bowls