Put 2 tablespoons flour into a good plastic bag. Add a little salt and pepper and shake to combine. Wipe veal pieces with a damp cloth to remove any bone dust. Place pieces of veal knuckle into bag and shake to cover each piece with flour. Place clarified butter and oil into a large skillet (frying pan) and heat to 400 degrees F. Place floured veal pieces into the butter/oil. They should foam and fry until golden. Turn to color evenly. Add the onions, garlic, carrots and orange zest. Toss veal pieces and vegetables together and lower heat to 300 degrees F. and allow to "sweat" (the natural oils "bead" out of the vegetables like perspiration) for 3 minutes. Now add 2 cups dry white wine and scrape pan base with wooden "spurtle" or spoon to lift up any sediment into the sauce. Reduce heat to simmer, add the bouquet garni (tie up with string if fresh or in a muslin bag if dried herbs are used) and the tomato paste which you need to stir in well. Simmer with a tight cover for 2 hours - adding another 1 1/4 cups dry white wine. About 30 minutes before serving add the orange juice. When the meat is very tender remove the veal pieces, pass the sauce and vegetables through a strainer and reheat the veal knuckle pieces in the sauce. Correct the seasoning and thicken, if necessary, with a little arrowroot paste. Dish the rice with the orange pieces on a large serving plate. Pile the veal pieces on top and coat with the sauce.