Prepare the ingredients:Gather you ingredients.Roughly chop the onion, carrot, and celery stalk. Crush the garlic cloves. Wash the bones with cold water.
Roast the bones:Bake the bones together with the vegetables at 230°C for about 60–90 min. 30 min in spread a thin layer of tomato paste on top of the bones. Return and cook for another 30-60min. Check them regularly, and if they start to burn, remove them from the oven.
Add the browned bones to a large pot.
Add enough cold water to just cover the bones (about 3 L in my case).
The roasting tray will have browned fond on the bottom; deglaze it with 200 mL of hot water.
Gently heat to a simmer: Using medium heat, bring the water to a gentle simmer. Do not boil! Skim the foam:Foam will start to appear on top of the liquid. Using a ladle, spoon or sieve carefully remove it. After 30 min add vegetables and the bouquet garni to the pot.
Simmer for 12h. Skim every 10–15 min for the first few hours. Check from time to time and if the water level drops, add enough water to again cover the bones.
Strain the liquid:Once the 12h have passed, strain the liquid through a fine sieve or cheesecloth. Do not push and force the meat and the bones, because the stock can cloud. Cool the liquid and store:Allow the stock to cool to 60°C (140°F) and then cool rapidly with ice or immediately refrigerate. After one night, any remaining lipids should be solidified on the top of the stock, so make sure to carefully remove it. You can keep the finished stock in the refrigerator for up to 3–4 days, or you can freeze it for long-term storage.