The 'Coals on Call' system was developed from a traditional French cooking style where a fire is kept burning at the back of the oven, providing the warmth. When you want to cook, hot coals are pulled forward from the base of the fire to provide the heat under the cooking grid or rotisserie, this method means that you have control over the intensity of the heat under the cooking area and provided that you keep the fire in the fire basket at the back of the BBQ well stocked you will never run out of fresh hot coals.