This section is from the book "The White Ribbon Cook Book", by Kathryn Armstrong. Also available from Amazon: The White Ribbon Cook Book.
Calf s head, 1 oz. of butter, 2 tablespoonfuls of flour, 1/2 pint of white stock, a few button mushrooms, white pepper and salt to taste, 2 eggs, juice of a lemon, parsley.
Cut the remnants of a boiled head into uni-form pieces the size of half an apple. Melt in a saucepan 1 or 2 ounces of butter, according to the quantity of meat to be hashed; amalgamate with it 1 or 2 tablespoonfuls of flour, then stir in 1/2 pint, more or less, of white stock. Stir well, then add a few button mushrooms, white pepper and salt to taste, and let the sauce boil for 10 minutes. Put the saucepan by the side of the fire, and lay the pieces of calf's head in it; let them get hot slowly, but not boil. Just before serving stir in off the fire the yolks of two eggs, beaten up with the juice of a lemon, and strained; also a small quantity of either tarragon or parsely very finely minced.
 
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