Veal Demi-Glace

Preheat the oven to 500 degrees. Place a large roasting pan in the oven for 10 minutes to preheat. Add the com oil and veal knuckles and roast for 25 minutes. Stir the bones and roast for another 5 minutes. Add the remaining ingredients, except the water, and stir. Roast for 15 minutes more.

Remove the pan from the oven and pour off any excess fat. Transfer the contents to a large pot and add the gallon of water. Place over high heat and bring to a boil, skimming off the impurities as they rise. Adjust the heat so the liquid is at a steady simmer. Cook for 3 hours.

Strain through a fine-mesh sieve. Degrease the stock by ladling off the grease as it rises to the top.

If you have more than 1 quart of stock, place it in a clean pot and boil until reduced to 1 quart. Store, tightly covered, in the refrigerator for up to 3 days, or in the freezer for up to 2 months.