Crème Agnès Sorel (chicken and mushroom velouté soup)

Poach the chicken breast in the clear chicken stock at a very gentle simmer, about 12 minutes, until white; cool completely and cut into matchsticks at the end.

Peel the mushrooms and slice off the pure white parts into matchsticks; keep the offcuts (a good 200 g) for the velouté, without the gills.

Squeeze lemon over the julienne.

Melt butter in a small pan on moderate heat, add the julienne without colouring, salt it (no pepper), add one or two tablespoons of water, bring to the boil and simmer five minutes (cuire à blanc).

Lift the julienne, without its lemony juice, into a bowl with a little chicken stock so it does not dry or blacken.

Melt all the butter in a rondeau, add the leeks and mushroom offcuts, and sweat on very low heat about five minutes without colour.

Add the flour on low heat, mix and cook the roux a good three minutes; turn off the heat and let it cool completely.

Off the heat, dilute the cold roux bit by bit with hot stock, whisking until no roux remains on the pan, then add the rest of the stock at once with a little pinch of rock salt.

Stir until it boils and thickens, boil a good minute, then simmer 25 to 30 minutes to concentrate the flavour and cook out the floury taste.

Pass through a sieve, pressing to extract the juices of the vegetables.

Return to high heat, add cream (up to 100 ml) for a whiter colour, bring to the boil, skim the scum and cook 10 minutes more to reduce.

Adjust salt and pepper; it should coat the back of a spoon.

Serve with the mushroom julienne and chicken matchsticks in the soup and a little parsley.