Have the butcher saw the veal shanks and beef ribs into small pieces. Rinse the chicken necks and wings thoroughly in cold water and pat dry with kitchen paper.
In a 180°C oven, roast the shank and rib pieces in one roasting pan with 2 tablespoons of oil, and the chicken in another with the remaining oil. Check periodically, turning the pieces to achieve a rich browning; it is worth the effort!
Meanwhile heat the extra vegetable oil in a 12-litre stockpot and sweat the vegetables over low to moderate heat for about 10-