Start cooking the shank: Coat the veal shank with a drizzle of olive oil and season with salt and pepper. Transfer it to a baking dish greased with 30 g of olive oil, along with the crushed unpeeled garlic cloves and rosemary sprigs. Pour over the white wine and place the dish in an oven preheated to 230°C (450°F) for 10–15 minutes. Cover tightly with aluminum foil, lower the temperature to 180°C (350°F), and continue cooking for 1 hour and 30 minutes.
Prepare the pomegranates: Cut the pomegranates in half. Seed one half (reserving the arils for garnish) and juice the remaining halves. Drizzle 2/3 of the pomegranate juice over the veal shank. Cover again with foil and continue cooking for another hour, basting the meat occasionally with the pan juices.
Finish and serve: Remove the foil and roast uncovered for 1 more hour, basting frequently with the juices. Meanwhile, heat 20 g of olive oil in a skillet, arrange the pearl onions in a single layer, and sprinkle with 1 teaspoon of sugar. Brown over medium-high heat on both sides for 2–3 minutes. Pour in the remaining pomegranate juice, cover, and simmer over low heat for about 20 minutes; adjust salt and pepper to taste. Add the onions to the shank dish, remove and discard the garlic cloves, and let the flavors meld together for 4–5 minutes. Transfer the veal shank, onions, and pan juices to a large serving platter, garnish with the pomegranate seeds, and serve immediately.