Place all ingredients except flour in 3 1/2- to 4-quart slow cooker, cutting beef to fit if necessary.
Cover and cook on Low heat setting 9 to 10 hours.
Remove beef to warm platter; cover with aluminum foil. Increase heat setting to High. Beat flour into hot cooking liquid, using wire whisk. Cover and cook 5 to 10 minutes, stirring occasionally, until mixture is thickened. Cut beef into 8 portions; serve with sauce.