Cut the meat into pieces about 2 in. square and put into a stew-pan with salt, sliced onion, herbs, peppercorns and nutmeg. Just cover with cold stock or water and simmer until tender—about 2 hr. When the meat is cooked, melt the butter in a saucepan and stir in the flour. Cook for a few minutes without browning. Strain ½ pt. liquor from the meat and add to the blended flour and butter. Stir until boiling, then simmer for 3 min. Beat together the egg yolk and cream and add to the sauce. Stir and cook gently for a few minutes, do not allow to boil or it may curdle. Correct the seasoning. Arrange the meat on a hot dish, piling it high in the centre and strain the sauce over.
Garnish with neatly shaped croûtes of fried bread or fleurons of pastry and grilled mushrooms. Serve hot.