Trim fat from roast; cut roast into 1-inch cubes. Place cubes and 1/4 cup flour in a plastic bag; seal bag, and shake vigorously to coat.
Pour oil into a large Dutch oven; place over medium-high heat until hot. Add beef, and cook, stirring occasionally, until browned.
Add 4 cups water and next 6 ingredients; bring to a boil. Cover, reduce heat, and simmer 2 hours or until tender.
Cut carrots and celery into 2-inch lengths. Peel potatoes; cut potatoes and onions into eighths. Cut bell peppers into 1-inch pieces.
Add carrots, celery, potatoes, onions, and bell peppers to beef mixture; cover and simmer 30 minutes or until vegetables are tender.
Combine 3 tablespoons flour and 3 tablespoons water, stirring well; stir into stew. Bring to a boil; boil, stirring constantly, 1 minute or until thickened and bubbly.
*2 pounds stew meat may be substituted for roast.