Drain fish, cool and cut into cubes. Prepare salad sauce by blending mayonnaise, sour cream, lemon juice, mustard, salt, and pepper. In a separate bowl gently mix fish cubes, egg and pickle slices and capers. Arrange fish mixture in individual dishes and spoon salad sauce over tops. Chill for 30 minutes. To garnish, cut remaining egg into eight pieces and chop beet slices. Arrange garnish on each serving. Serve immediately.