|Method:||Put the stock into a stewpan, with the parsley, cloves,
bay-leaf, herbs, and mushrooms; add a seasoning of salt, but no pepper,
as that would give the sauce a dusty appearance, and should be avoided.
When it has boiled long enough to extract the flavour of the herbs,
etc., strain it, and boil it up quickly again, until it is nearly
half-reduced. Now mix the arrowroot smoothly with the cream, and let it
simmer very gently for 5 minutes over a slow fire; pour to it the
reduced stock, and continue to simmer slowly for 10 minutes, if the
sauce be thick. If, on the contrary, it be too thin, it must be stirred
over a sharp fire till it thickens. This is the foundation of many kinds
of sauces, especially white sauces. Always make it thick, as you can
easily thin it with cream, milk, or white stock.