Mix 1 egg, milk, flour and a pinch of salt to a dough. Let dough rest for about 30 minutes. Brush the pan (28 cm Ø) with oil and bake 2 thin crêpes one after the other. Remove the crêpes from the pan and let them cool down briefly.
Remove the fat edge of the salmon ham. Spread 6 slices of salmon ham on each crêpe. Wash the parsley, dab dry and place some leaves on the ham. Roll up crêpes tightly. Wrap crêpe rolls in foil and chill.
Boil 2 eggs in boiling water for 9 minutes, quench in cold water and let them cool down. Wash and peel the asparagus and cut off the woody ends. Cook the asparagus spears in boiling salted water with 1 pinch of sugar for 15-18 minutes.
Peel and finely chop the onion. Mix onion cubes, mustard, vinegar and 5 tablespoons asparagus stock. Gradually add the oil and season to taste with salt, pepper and a little sugar. Peel and chop the eggs.
Wash remaining herbs, dab dry. Finely chop all herbs (except for a few chervil twigs for garnishing). Add the egg cubes and herbs to the vinaigrette. Remove crêpe rolls from the foil and cut into slices.
Remove asparagus from the stock and arrange on plates with the crêpe snails. Pour herb and egg vinaigrette over the asparagus. Garnish with chervil.