Tie each veal slice around its girth with kitchen string to hold it in a compact circle. Season the slices with salt and pepper, then dredge them in the flour, shaking off the excess. In a large skillet or sauté pan, heat the oil over medium-high heat. Add the veal slices, in one layer, and cook for 5 minutes on each side to brown well. Arrange the slices in a 6- to 7-quart slow cooker and return the skillet to high heat. Add the wine to the skillet and use a spatula to scrape up the browned bits on the bottom. Boil the wine for 2 minutes, then pour it over the veal.

Scatter the onion, carrots, celery, garlic, and thyme over the veal. Chop the tomatoes and add them, with their juices, to the cooker. Sprinkle 1 teaspoon salt and ½ teaspoon pepper over the vegetables and veal. Cook, covered, on the low setting for 4 to 5 hours, until the veal is tender and the vegetables are soft. Thirty minutes before the end of the cooking time, add the olives and artichoke hearts. Season to taste with salt and pepper.

To make the gremolata, very finely mince the parsley and zests together on a board. Remove the strings from the veal slices. Place one veal slice on each of 4 individual serving plates and spoon some of the sauce and vegetables over it. Sprinkle the gremolata on top and serve immediately.