Demi-Glace Recipe

Preheat oven to 450 degrees F (230 degrees C). Place veal bones in a roasting pan.

Roast bones in the preheated oven until well-browned about 75 minutes.

While bones are roasting drizzle oil onto a baking sheet. Spread onion carrots and celery onto baking sheet; spread tomato paste over the vegetables and mix to coat.

Roast vegetable mixture in the preheated oven until vegetables are well-browned about 45 minutes.

Transfer vegetable mixture and bones to a large stockpot. Pour 10 quarts water into stockpot.

Pour 2 cups water into the bones roasting pan set the pan over high heat and bring to a boil while scraping the browned bits of food off of the bottom of the pan with a wooden spoon. Pour liquid into the stockpot with the bones.

Bring bones vegetables and water in the stockpot to a boil reduce heat to low and simmer gently skimming foam as necessary until meat and all connective tissue is completely off the bones about 18 hours.

Set a colander over a bowl and ladle vegetables bones and meat into colander. Discard vegetables bones and meat; return any broth to the stockpot.

Bring broth to a boil; cook at a boil until liquid reduces to approximately 1 gallon in volume 30 minutes to 1 hour.

Strain broth through a fine-mesh strainer into a large container set in an ice bath; chill to room temperature. Cover the container with a lid or plastic wrap and chill in the refrigerator until demi-glace is cold and set 8 hours to overnight.