A cooking system includes a housing defining a hollow chamber configured to receive food. The housing has an upper portion defining an opening to said hollow chamber. A lid is movable relative to the housing between an open position and a closed position and has an interior lid cavity. An air movement device is positioned to move air through at least one of the hollow chamber and the interior lid cavity in a direction of flow. At least one vent is disposed in at least one of the lid and the housing and includes a leading end and a trailing end relative to the direction of flow. The at least one vent is openable to have a greater airflow capacity at the leading end relative to the trailing end or openable to have a greater airflow capacity at the trailing end relative to the leading end.