Prepare the veal shanks: Pat the veal shanks dry with paper towels. Season generously with salt and pepper, then dredge in flour, shaking off excess.

Brown the veal: Heat olive oil in a large Dutch oven over medium-high heat. Brown the veal shanks on both sides, about 4-5 minutes per side. Remove and set aside.

Sauté vegetables: In the same pot, add onion, carrots, and celery. Cook until softened, about 5 minutes. Add minced garlic and cook for 1 more minute.

Deglaze with wine: Pour in white wine, scraping up any browned bits from the bottom of the pot. Let simmer until reduced by half, about 3-4 minutes.

Braise the veal: Return veal shanks to the pot. Add stock, tomatoes, bay leaves, and thyme. Bring to a simmer, then cover and reduce heat to low. Cook for 1.5-2 hours until meat is tender.

Make gremolata: While the veal cooks, mix parsley, lemon zest, and minced garlic in a small bowl. Set aside.

Serve: Remove bay leaves. Sprinkle gremolata over the osso buco before serving. Traditionally served with risotto or polenta.