1. Cook beef on a pan - and seasoned as desired

2. Mix the flour, mustard and salt pepper - and toss it on the beef

3. Place the beef on the crockpot

4. Cover the beef with the onions and mushrooms, add beef broth and wine

5. Cover and cook on LOW for 8 or 10 hours

6. Before serving combine with sour cream and 1/4 cup of flour

7. Stir into the crockpot and cook for another 10 to 15 minutes or until stroganoff thickens slightly