Dredge the veal shanks in the flour and shake off excess. Heat the olive oil in a deep sauté pan over medium heat. Brown the meat on both sides, turning the shanks occasionally. Remove the meat from the pan. Add the carrot, onion, celery and garlic and cook the vegetables for 3-4 minutes, stirring them occasionally. Add the lemon peel, wine, stock, tomatoes and tomato paste to the pan and stir them in. Bring the ingredients to a simmer. Return the meat to the pan. Sprinkle the ingredients with the salt, pepper and basil. Cover the pan and simmer over low heat for about 2 hours or until the meat is very tender.