Preparation / Directions:
1. Trim fat from steak. Wrap steak in heavy-duty plastic wrap; freeze 30 minutes. Unwrap steak; cut steak diagonally across grain into 1/8-inch thick slices. Place steak, onion, and next 7 ingredients in a 3-quart electric slow cooker. combine flour and broth in a bowl; stir with a whisk until blended. Add broth mixture to cooker; stir well. Cover; cook on low-heat setting for 8 hours or until tender. Turn slow cooker off; remove lid. Let stand 10 minutes. Stir in sour cream. Serve stroganoff over noodles.