In a baking-serving casserole, heat the oil, then add the veal and saute on all sides. Add the garlic and season with salt and pepper. Stir with a wooden spoon, then add the vinegar, wine, tomatoes, bay leaf, sugar, and enough water to cover the veal. Arrange the onions over the meat, sprinkle the parsley and butter bits over the top, and slip the spices in between the meat and the onions. Shake the casserole a few times, then cover with an inverted plate to keep in place and cover tightly with a lid (using a little flour-water paste around the inside of the lid to seal if you wish). Bake in a slow oven (300 F) for 2 to 2-1/2 hours or over minimum heat on a burner, until the veal and onions are tender. Remove from the heat and serve warm. Note: After peeling the onions, pierce the root end of each onion with the tip of a small, sharp knife, then slash again at a right angle to make a cross. This will keep the onion whole and intact during the cooking process.