Peel outer layer off onions. Slice a small section off of one end of each onion, and make a small hole in the center. Fill the center of each onion with a bouillon cube and 2 tablespoons butter or margarine. Replace the top of the onion, and wrap in aluminum foil.
Place onions on grill over indirect heat, and close the lid. Cook for 1 hour, or until tender. Remove the tops, and cut into bite size chunks. Place in a serving dish with all the juices from the foil.
