"To make a purée of mushrooms, select such as are of a globular shape,
called 'button-mushrooms;' wash them in cold water and wipe them dry;
chop them as fine as possible and press them in a cloth; put them in a
stewpan with a little butter and pepper; let them stand over a brisk
fire, and when the butter is melted squeeze in lemon-juice and add
jelly broth, according to the quantity of the mushrooms. Stew until
reduced to the consistency of pea-soup, and serve with meat, fish, or
poached egg."--_Cooke_.