Abstract: An adjustable oven for mass cooking of food products comprising an essentially sealed enclosure having a conveyor received therethrough for conveying food through the oven. A heated gaseous cooking medium is applied to the food product during conveyance through the oven by impingement of the cooking medium at high velocity through spaced duct fingers disposed above and below the conveyor system. The gaseous cooking medium is heated and circulated through the oven at high velocity and subsequently recirculated for continuous cooking of food products in the oven. The cooking oven enables optimization of the cooking process by allowing at least certain of the duct fingers to be vertically adjustable relative to the food product so as to maximize heat transfer therefrom for any particular food product.