Preheat oven to 400 F. Combine rice, broccoli & cheese with 2/3 margarine/spice mixture. Spread 2/3 of the filling evenly over salmon; pat down. Using the help of the plastic bag, roll filled salmon up in a jelly-roll style. Line a 9 x 13-inch baking pan with foil & spread remaining filling in it. Place salmon roll on top, pushing under layer close up around roll. Spread remaining butter sauce over salmon roll. Bake for 20-25 minutes. Slice & serve.