A cooking appliance includes a heating system capable of combining radiant, convection, microwave and conduction heating techniques to perform a cooking operation. The cooking appliance includes a cooking chamber and a bifurcated air plenum having an angled divider that defines a tapered air delivery portion and a tapered exhaust portion. The tapered air delivery portion actually guides a convective air flow through an air emitter plate positioned at a top of the cooking chamber. The air emitter plate includes a recessed, serpentine-like channel having a plurality of openings that lead to the air delivery portion. A radiant heating element is nested within the recessed channel. The cooking appliance further includes a convection fan, as well as a magnetron having a rotatable antenna positioned below the cooking chamber and a conductive plate upon which food to be cooked is supported.