Sauce Piquante au Citron

(For Calf’s Head)

2 table-spoons chopped onions
1 oz. butter
1 table-spoon flour
1 gill white stock
1 gill white wine
1 lemon

Fry the onion in the butter, with the flour, until a rich yellow. Add to it the stock, which should be boiling, and the wine. Stir together. Add the juice of the lemon and a little of the grated rind. Simmer for quarter of an hour. Strain through a fine sieve.