This section is from the book "The Epicurean", by Charles Ranhofer. Also available from Amazon: The Epicurean, a Complete Treatise of Analytical and Practical Studies on the Culinary Art.
Cut half a pound of carrots, half a pound of onions, half a pound of celery root and two ounces of parsley root into either three-sixteenth inch squares or small Julienne; fry them lightly without coloring in half a pound of chopped up fat pork, and add to them half a pound of ham cut either in squares or Julienne shape, also a quarter of a pound of mushrooms, a few branches of parsley (about half an ounce), two bay leaves, as much thyme and a teaspoonful of mignonette; moisten with a pint of white wine and a pint of veal blond (No. 423); boil and reduce the moisture to a glaze.
Put four ounces of scraped fat pork and butter into a saucepan, and when well melted add to it six ounces of either chopped or one-eighth of inch pieces of shallot, a clove of crushed and chopped garlic, lei these ingredients fry without coloring, adding half a pound of raw, finely chopped mushrooms; set it on the fire, and reduce while stirring continuously until the moisture from the mushrooms be entirely evaporated, then add an ounce of chopped parsley washed and pressed out; an ounce of chopped truffles may be added, but this is optional. If it needs to be thickened add to it half a pint of demi-glaze sauce (No. 413), and reduce until it acquires a consistency.