Cut the chicken into cubes of a half inch. Boil the sweetbreads and pick them apart, rejecting the membrane. Drain and wash the mushrooms, cut them into halves and mix them with the sweetbread and chicken. Rub the butter and flour together, and add the milk; when boiling, add salt, pepper, onion juice and meat. Stand this over hot water in a covered saucepan for twenty minutes, add the yolks of the eggs, slightly beaten, and bring just to boiling point.
Served in ramekins or paper cases this is sufficient for fifteen persons. Served as a supper or luncheon dish alone, twelve persons.