Russian Soup
2 kidneys
2 small onions
¹⁄₄ lb. mushrooms
1 dozen small olives
3 gherkins
1 quart strong stock
Yolks of two eggs
Melt the butter and fry the kidneys and onions (finely cut up) in it very gently for five minutes. Cook the mushrooms separately. Put the kidneys, onions, mushrooms, olives and gherkins (finely sliced) in a hot soup tureen. Pour over them a quart of rich, dark, well-seasoned brown stock, which has been thickened with the yolks of two eggs.