Clean the artichoke hearts, divide them into 4 to 6 pieces and leave them in salted water for 10 min to prevent them from darkening. Later make the artichoke hearts half an hour.
In the meantime cook a roux with the flour and butter, extinguish with the clear soup.
Pass the artichoke hearts through a sieve, add milk, egg yolk and whipped cream and mix in the hot soup. Season to taste with salt and freshly ground pepper.