Cut beef into 6 serving pieces. In small bowl, mix flour, mustard and salt. Sprinkle half of the flour mixture over 1 side of beef; pound in with meat mallet. Turn beef; pound in remaining flour mixture.
In 10-inch skillet, heat oil over medium heat. Cook beef in oil about 15 minutes, turning once, until brown.
Add tomatoes and garlic to skillet, breaking up tomatoes with a fork. Heat to boiling; reduce heat. Cover and simmer about 1 hour 15 minutes, spooning sauce occasionally over beef, until beef is tender.
Add water, onion and bell pepper to skillet. Heat to boiling; reduce heat. Cover and simmer 5 to 8 minutes or until vegetables are tender.