Trim fat from brisket. Place brisket in a large stockpot; add water. Bring to a boil; cover, reduce heat, and simmer 2 hours or until tender. Remove brisket from pot, and set cooking liquid aside. Place brisket in a large baking dish; drizzle with syrup. Bake, uncovered, at 400° for 20 minutes.
Add onions and next 3 ingredients to stockpot; bring to a boil. Cover and cook 20 minutes. Add cabbage; cover and cook an additional 5 minutes or until the vegetables are tender. Remove vegetables with a slotted spoon, and place on a serving platter. Thinly slice brisket, and place on platter.
Drizzle drippings from baking dish over sliced brisket.
