Scrub potatoes and cut each into quarters. Place in bottom of 4 quart slow cooker. Mix flour, salt and pepper and toss with beef to coat. Add to crockpot. Add undrained tomatoes and water and stir.
Cover crockpot and cook on low for 7-8 hours until beef and potatoes are tender.Add stir fry vegetables. Cover and cook on low for 30-40 minutes until vegetables are hot and tender. 4-6 servings