1. In a bowl combine the flour, ½ teaspoon of the salt and ½ teaspoon of the pepper, or more to taste. Add the veal and toss until the cubes are completely coated.
2. Remove the meat from the flour, sifting it through your hands to shake off the excess flour. Saute the veal in the butter and oil in an 8- to 10-quart Dutch oven over medium-high heat, stirring frequently, until brown on all sides, about 5 minutes.
3. Add the onions and garlic and cook, stirring frequently, until the onions are soft, about 5 minutes. Add all of the remaining ingredients, except the yogurt or sour cream, and stir until well mixed.
4. Cook covered, over high heat until the liquid boils. Season with salt and pepper to taste.
5. Place in a preheated 350°F oven. Bake stirring several times during cooking, until the vegetables are very tender, about 1 hour. Serve hot. Garnish each serving with yogurt or sour cream.
