Sprinkle meat with seasonings. Place onions, carrots and celery in crockpot. Top with meat and add bay leaf, vinegar, and water. Cover pot and cook on low for 5 to 7 hours. Remove meat; turn to high. Add cabbage; cover and cook on high for 15 to 20 minutes or until cabbage is done.

Meanwhile melt butter in saucepan. Stir in instant onion and flour. Drain 1 1/2 cups broth from crockpot. Pour broth, horseradish and salt into saucepan. Cook over low heat, stirring constantly, until thickened.

NOTE: when adding cabbage, wait until crockpot reaches the high temperature. This may take a few minutes since the cover has been removed and much heat has been lost.