Ingredients

• 8 to 10 (10-oz) meaty cross-cut veal shanks (osso buco; 5 to 6 1/2 lb total), each tied with kitchen string
• 1/2 cup all-purpose flour
• 2 tablespoons olive oil
• 3 tablespoons unsalted butter
• 2 medium onions, halved lengthwise and thinly sliced
• 1 small carrot, finely chopped
• 1 celery rib, finely chopped
• 2 garlic cloves, finely chopped
• 1 cup dry white wine
• 1 cup chicken broth
• 1 (28- to 32-oz) can whole plum tomatoes with juice (not in purée), coarsely chopped
• 1 cup Kalamata or other brine-cured black olives, pitted and halved
• 1 1/2 teaspoons fresh thyme leaves
• 2 fresh flat-leaf parsley sprigs
• 1 Turkish or 1/2 California bay leaf
• 2 (2- by 1/2-inch) strips fresh lemon zest , cut crosswise into fine julienne
• 1 teaspoon salt, or to taste
• 1/2 teaspoon black pepper, or to taste
• 3 tablespoons chopped fresh flat-leaf parsley
• 1 large garlic clove, minced
• 1 teaspoon finely grated fresh fresh lemon zest
• a 7- to 9-quart heavy ovenproof pot (wide enough to hold shanks in 1 layer)

Instructions

1. Preheat oven to 325°F.
2. Pat shanks dry and season with salt and pepper. Divide shanks and flour between 2 large sealable plastic bags and shake to coat, then remove shanks from bags, shaking off excess flour. Heat oil and 2 tablespoons butter in ovenproof pot over moderately high heat until foam subsides, then brown shanks well in 2 batches, 10 to 12 minutes per batch, transferring to a plate.
3. Reduce heat to moderate and add remaining tablespoon butter to pot along with onions, carrot, celery, and garlic and cook, stirring, until onions are pale golden, about 5 minutes. Add remaining stew ingredients and bring to a boil, stirring. Arrange shanks in pot in 1 layer and return to a simmer. Cover pot and braise shanks in middle of oven until very tender, about 2 1/2 hours. Remove strings from osso buco and discard along with parsley sprigs and bay leaf.
4. Stir together gremolata ingredients in a small bowl and sprinkle over osso buco. Serve immediately.