Cut onions in half lengthwise, and slice. Set aside.
Place flour in a large heavy-duty zip-top plastic bag; add roast. Seal bag, and shake until roast is coated.
Brown roast in hot oil in a Dutch oven. Add sliced onion, broth, and remaining ingredients; bring to a boil. Reduce heat, cover, and simmer 2 to 2 1/2 hours or until roast is tender. Discard bay leaves.