1. Place the flour on a plate. Dredge the beef cubes in the flour.
2. In a large, heavy saucepan, heat the oil over medium heat. Cook the beef until browned on all sides (5 minutes). Remove the beef from the pan with a slotted spoon and set aside.
3. Add the fennel, garlic, and shallots to the pan over medium heat and saute until softened and lightly golden (7-8 minutes). Add salt, pepper, thyme, and bay leaf. Saute for 1 minute.
4. Return the beef to the pan and add the stock and wine, if using. Bring to a boil, then reduce the heat to low. Cover and simmer gently until the meat is tender (40-45 minutes).
5. Add the carrots, potatoes, onions, and mushrooms. Simmer gently until the vegetables are tender (30 minutes). Discard the thyme sprigs and bay leaf. Stir in the parsley to serve.