There is provided a modular barbecue system and kits for adapting a gas barbecue to other types of cooking and other uses. The modular barbecue system comprises a heating compartment having a bottom wall and a peripheral defining a cavity, a heat source provided in the cavity of the heating compartment, a plurality of add-on components receivable in the cavity of the heating compartment, a plurality of steps provided in the cavity of the heating compartment for supporting the add-on components at different distances relative to the heat source. Add-on components such as a large basin, a flat basin, a perforated plate system, a strainer, a lid and a pump are combined to form a plurality of kits enabling steam cooking, maple sap boiling, double boiling, coal fire cooking, boiling, smoke cooking and water heating to expand the typical grilling method of a gas barbecue to various cooking techniques.
