Fine-Herbs Sauce

First chop very fine the following ingredients: viz. a dozen mushrooms, four shalots, and a little parsley; put these into a small stewpan with a bit of butter, stir over the fire for five minutes, then add a gill of brown sauce, No. 12 (or a spoonful of flour and a gill of gravy), the juice of half a lemon, nutmeg, pepper, and salt, and a pinch of sugar; boil for a few minutes, and serve as directed.