Have three pounds of shoulder of lamb cut into pieces about two inches square. Wash well in fresh water, drain, put into a saucepan, and cover with fresh water. Let it come to a boil, then strain through a colander, and wash again in water. Place the pieces in a saucepan, covering them with boiling water; season with two tablespoonfuls of salt, one teaspoonful of pepper, six small onions, and a bouquet (No. 254). Put the lid on, and cook forty minutes. Then strain off the liquor into another saucepan containing half a pint of roux blanc (No. 135), stirring well until it boils, and then let it stand on the corner of the stove. Break into a separate bowl four egg yolks with the juice of half a lemon, beaten well together. Add this to the sauce, dropping it in little by little, and stirring continually. Pour all over the lamb, and add one pint of cooked asparagus-tops, but be careful not to let it boil again. Serve with a border of hot, boiled rice all around the dish.