In a large soup pot, deeply brown the meat in oil. Stir in onions, garlic. Worcestershire sauce, bay leaf, thyme, salt and 3 cups of water. Simmer, covered, for 1 1/2 to 2 hours, or until meat is tender.
Stir in potatoes and parsnips; cook until tender.
Combine flour and 1/4 cup water. Stir into the stew.