Put two tablespoonfuls of finely-chopped onions into a stewpan with a
piece of butter the size of a walnut; stir them over the fire until
lightly browned; then add eighteen spoonfuls of demi-glace (No. 9), and
eight of consommé (No. 134), reduce it to two thirds, skim it well, then
add a tablespoonful of chopped parsley, and one of chopped mushrooms,
with a little cayenne pepper, and a quarter of a teaspoonful of powdered
sugar; boil altogether five minutes, and finish with the juice of half a
lemon; it is then ready for use.