When made from tinned mushrooms, simply chop up the mushrooms, reserving the liquor, then add a little cream and thicken with a little white roux.

A little pepper and salt should be added in both cases.
Instead of using either milk or cream, you can use a small quantity of sauce Allemande.
MUSHROOM SAUCE, BROWN .-- Proceed exactly as above with regard to the mushrooms, both fresh and tinned, only instead of adding milk, cream, or Allemande sauce, add a little stock or water, and then thicken the sauce with a little brown roux.
MUSHROOM SAUCE, PUREE .-- Mushroom sauce, both white and brown, is sometimes served as a puree.

It is simply either of the above sauces rubbed through a wire sieve.
MUSTARD SAUCE .-- Make, say, half a pint of good butter sauce, add to this a tablespoonful of French mustard and a tablespoonful of made English mustard.

Stir this into the sauce, make it hot, and serve.
N.B .-- French mustard is sold ready-made in jars, and is flavoured with tarragon, capers, ravigotte, &c.
ONION SAUCE .-- Take half a dozen large onions, peel them and boil them in a little salted water till they are tender.

Then take them out and chop them up fine, and put them in a stew-pan with a little milk.