Place beef, water, onions, catsup, pepper, thyme, garlic powder, bay leaves and salt in steam-jacketed kettle or stock pot. Bring to a boil; reduce heat; cover; simmer about 2-3 hours or until tender. Skim off excess fat. Remove bay leaves.
Add noodles to boiling salted water; return to a boil; cook 8 to 10 minutes or until tender; drain thoroughly.
Combine flour and water to make smooth mixture; stir into beef mixture. Blend well. Return to boil. Reduce heat; cook 10 minutes or until thickened.