A universal, adjustable, and removable heat and flavor diffuser for a grill that is selectively removably coupled to a grill assembly, namely disposed within a pellet grill and disposed above a heat source, primarily a fire pot, thereon. The present invention comprises a platform body coupled to, separating, and supported by two opposing legs, the platform body defining an enclosed tray aperture wherein a diffusing tray is selectively removably inserted therein. The sidewall and the bottom wall of the diffusing tray define a diffusing cavity designed to house liquid and/or solid flavor enhancers, such as smoking chips, chunks, pellets or aromatics. A diffusing lid is selectively removably coupled to the diffusing tray. All of the foregoing features may be of a substantially rigid and heat-resistant material composition, plating, or coating.