Combine 1/2 cup flour, 2 tsp salt and 1 tsp pepper in resealable plastic food storage bag. Add beef and shake bag to coat beef. Transfer to slow cooker. Add remaining ingredients. Stir well.
Cover. Cook on LOW 8 - 12 hours or on HIGH 4 - 6 hours. One hour before serving, turn slow cooker to HIGH. Whisk together remaining 2 tablespoons flour and water in small bowl. Stir into slow cooker. Cover. Cook until thickened.