No. 185 Rich White Sauce
1½ ounces butter.
½ ounce flour.
Yolk of one egg.
¼ pint each milk and water.
A pinch of salt.
Prepare sauce same as No. 184, and stand the saucepan on one side for ten minutes, then drop into it the yolk of an egg, and stir over a gentle heat for a few minutes, but on no account allow it to boil again, or the sauce will curdle.