White and brown veal gravy

Ingredients . 1 Kg of bones and veal leftover . 1 small onion . 1 carrot . 1 garlic clover . 1 bouquet garni
1. Ask your butcher to reserve veal leftovers. He will do so graciously. Put all ingredients in a stewpot, cover largely with cold water and start cooking over medium heat, boil until the broth has reduced by 3/4. This may take several hours. Place your gravy in an airtight container for cooling. The fat rises to the surface, and once solid, you can remove it very easily. Your gravy is ready.
2. For brown gravy, you must place the bones in advance in oven at 200 degrees Celsius (before cooking with water) for at least 30 minutes in order to obtain well coloured bones. You can freeze your veal gravy on the condition of previously cooling it very quickly, because bacteria grow rapidly in this kind of preparation. In liquid form the maximum conservation period is 24 hours.