Put the butter into a saucepan. Add the onion and garlic. Cook until all are browned; then add three tablespoonfuls of water in which the macaroni was boiled, and the beef extract. Add, also, the soaked mushrooms, and let it simmer for five minutes.
This amount of sauce is enough for a pound of macaroni.
The mushrooms given in this receipt are the dried cepes, which can be bought by the pound at Italian groceries. They are the best, after the fresh mushrooms, to use for sauces. They should not be cooked longer than five minutes to give their best flavor.