Slowly makes about 4 litres of stock.
- 4 kg beef bones, including knuckle bones, trimmings, etc., cut (with the saw?) into smallish pieces
 - Oil
 - 100g tomato paste, thinned with 2 tablespoons water
 - 6-7 litres cold water
 - 600g mirepoix:
 - 300g onions, coarsely chopped
 - 150g carrots, coarsely chopped
 - 150g celery, coarsely chopped
 - 300g tomatoes, quartered
 - Sachet d’epices:
 - 3 or 4 parsley stems, chopped
 - 1/2 teaspoon thyme leaves
 - 1 bay leaf
 - 1 whole clove
 - 1/2 teaspoon cracked black peppercorns
 - 1 clove garlic, crushed
 
The spices above are placed into a small square of cheesecloth and tied into a sack (hence un sachet?).
- Heat the oven to 400F/200C.
 - Lightly oil sheet pan and place in the oven to heat.
 - Place the bones on the sheet pan and roast for 30 minutes, turning occasionally.
 - Paint the bones with a thin layer of the thinned tomato paste, and roast for an additional 30 minutes, turning occasionally, until evenly browned.
 - Place the bones in the stockpot and cover with cold water. Bring to a boil, and then lower to a simmer.
 - Skim any scum that forms on the surface gradually as needed.
 - Drain and reserve the fat from the pan; deglaze the pan with water and add to the stockpot.
 - Continue to simmer the stock for 6-7 hours, skimming as needed. If necessary, you may add more hot water to keep the bones covered.
 - Toss the mirepoix with the fat and brown in the oven.
 - Add the browned mirepoix, tomatoes and sachet to the pot.
 - Simmer for another 1-2 hours.
 - Strain the stock through a china funnel layered with cheesecloth, and cool the stockpot in an ice-water bath.
 - Transfer to a container and refrigerate overnight; the next day, skim off all the fat that’s risen to the surface.