Abstract: An apparatus is provided for heating and processing a product. A mixing bowl includes a rounded base portion, an extended upper portion and two end walls. An agitator is positioned within the base of the bowl for rotation about a rotational axis and in a closely spaced relation with the bowl. The agitator includes a drive shaft having a portion thereof projecting outwardly of the mixing bowl. The agitator having a rotational path closely spaced with the inside wall of the base portion and spaced from the upper portion of the bowl. An outwardly flared transition maybe provided between the base and upper portion of the bowl. A microwave energy source is directed into the bowl for heating the product. A choke surrounds the agitator shaft to form a seal for the bowl to prevent microwave leakage.