In a shallow bowl, mix flour with salt and freshly ground black pepper. Dredge veal pieces in flour mixture and set aside. In a 12 to 14-inch saute pan, heat olive oil over medium high heat until just smoking. Shake excess flour from veal and place pieces in pan. Cook until golden brown on one side, about 5 to 6 minutes. Turn and continue cooking until golden brown, about 4 to 5 minutes. Remove veal pieces and pour out oil.
Add 1/2 cup water to pan and deglaze, scraping lightly with a wooden spoon to loosen brown bits. Add tomato sauce and bring to a boil. Replace veal in pan and coat with sauce. Place 2 pieces of fresh mozzarella over each piece of veal and place pan in a preheated 350 degree oven for 6 to 8 minutes, or until cheese is melted. Remove pan from oven.
Place veal on platter, surround with sauce, sprinkle with fresh oregano and serve.
Recipe Courtesy of Mario Batali