Wash and peel the asparagus and cut off the woody ends. Cook in boiling salted water for about 15 minutes. Drain and cut into small pieces. Drain the asparagus peel in the asparagus stock for about 15 minutes, catch the stock. Defrost the peas.
Wash the tomatoes, quarter them, remove the seeds and cut them into slices. Wash the tips of the fillet, dab dry and cut into small pieces. Peel onion and chop finely. Fry onion and meat in hot oil, turning. Deglaze with 3/4 litre asparagus stock and bring to the boil. Knead fat and flour and thicken the sauce. Warm the asparagus, peas and tomatoes. Whisk cream and egg yolk, stir into the ragout and do not let it boil. Season to taste with salt, pepper and lemon juice.
Knead fat and flour and thicken the sauce. Warm the asparagus, peas and tomatoes. Whisk cream and egg yolk, stir into the ragout and do not let it boil. Season to taste with salt, pepper and lemon juice. Serve sprinkled with chervil leaves. Serve with croquettes
Preparation time approx. 1 hour