Cut Fish Into Serving-Size Pieces; Place In An Ungreased Shallow Microwave-Safe Dish. Cover And Microwave On High For 4 Minutes. Drain Liquid. Combine The Sour Cream, Mayonnaise, Milk, Mustard And Dill; Drizzle 1/2 Cup Over The Fish. Microwave, Uncovered, On High For 4 Minutes Or Until Fish Flakes Easily With A Fork. Serve Over Rice With Remaining Sauce.