Preheat oven to 350 degrees. Place flour and salt and pepper in a shallow dish. Lightly coat shanks with flour. Heat oil in a saucepan over high heat. Cook shanks, in batches, for 3 to 4 minutes or until browned. Transfer to a large roasting pan.
Add onions and garlic to saucepan. Cook over medium heat for 2 to 3 minutes or until soft. Add consommé, wine and maple syrup. Stir to combine. Bring to the boil. Season with salt and pepper. Pour over shanks and cover pan tightly with foil. Roast for 1 1/4 hours. Remove foil. Turn shanks and roast for 45 minutes or until tender.
Transfer shanks to a platter and cover to keep warm. Strain cooking liquid through a sieve. Discard onions. Return liquid to pan. Mix corn flour and water in a bowl until smooth. Stir into liquid and bring to the boil, stirring, over high heat. Reduce heat to medium-low and simmer for 5 minutes or until reduced slightly. Serve shanks with gravy, cheese and herb mash and steamed cabbage (see related recipes).