Saute Onion In Butter Until Browned. Sprinkle In Flour And Saute For 1 Minute. Stir In Paprika. Add Meat, Saute Until Browned Slightly. Season With Salt And Pepper. Add Stock And Bay Leaf. Cover, Simmer For 20 Minutes. Add More Water Or Beef Broth As Needed To Keep Meat Covered. Add Sour Cream, Remove From Heat And Serve.