In order to smoke on a gas grill that doesn’t have a smoker box, I like to make a smoker pouch. This is easy to do with a piece of heavy-duty aluminum foil. Once the chip-filled pouch is made, you place it under the grate over one of the burners as shown at left. When the smoker pouch is in place, run the grill until a thick plume of smoke emerges. With many gas grills, you have to preheat the grill to high to get the chips smoking, then reduce the heat to the desired temperature when you’re ready to start cooking.