Crockpot Swiss Steak

I'm trying this tonight. I love crock pot recipes and this looks like a good one. I'll post the results. Enjoy!

2 tablespoons flour
1/2 tsp. salt
1/4 tsp. pepper
1 1/2 to 2 lb. round steak, cut in serving portions
1/2 cup chopped onion
2 tbsp. butter
1 can tomato soup or a can (14.5 ounces) stewed tomatoes
1/2 c. water (if using tomato soup)
1 1/2 tsp. vinegar
Preparation:
Combine flour, salt, and pepper; using a meat tenderizer or rolling pin, pound mixture into steak. Brown steak in butter with chopped onion. Add tomato soup, water, vinegar; transfer to crockpot. Cover and cook on LOW for 6 to 8 hours, or on HIGH for 3 to 4 hours.
Serves 6 to 8.