Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   2      pounds        beef to round steak -- trimmed fat
     1/2  pound         fresh white mushrooms -- sliced
   1      bunch         scallions -- choped
   1      medium        onion -- sliced
     1/4  teaspoon      dried thyme leaves
     3/4  cup           dry sherry
     3/4  cup           homemade or canned beef broth
     3/4  teaspoon      dry mustard
     1/4  teaspoon      garlic pepper
   1 1/2  cups          sour cream
     1/2  cup           quick-mixing flour -- such as wondra

Preparation:

1. Cut the beef into thin slices across the grain. PLace in a 4-quart electric slow cooker. Add the mushrooms, scallions, onion, thyme, sherry, broth, dry mustard, and garlic pepper. Mix well. 2. Cover and cook on the low heat setting about 8 hours, or until the beef is tender, stirring once, if possible. Increase the heat setting to high. 3. Mix together the sour cream and flour until thoroughly blended. Stir a little of the hot liquid from the slow cooker into the sour cream mixture; then stir the sour cream mixture into the slow cooker, mixing well. Cover and cook on high 30 to 40 minutes, or until thickened slightly.