Put a pint of white stock (or water) into a saucepan with an onion in which two cloves have been stuck, a blade of mace, salt and pepper to taste, and let it boil gently for half an hour. Melt an ounce of butter in a stewpan and stir in gradually two large tablespoonfuls of flour, and when it is well mixed add the stock by degrees; let it boil up and simmer for five minutes, then pour in sufficient milk to make the sauce white and slightly thinner; strain it and put it aside until it is required. Spread about two pounds of fillet of veal out on a board, and cover it with a layer of sausage-meat, then roll it up, secure it with tape and fry it for ten minutes in a small quantity of clarified dripping without letting it acquire any color. Then place it in a stewpan, cover it with the prepared sauce and let it cook gently in a moderately hot oven for three hours. Remove the tape when the meat is ready, and place it on a hot dish; add a dessertspoonful of parsley to the sauce and pour it over the veal.