An oven includes a conveying interior for moving produce through the oven and a gas fired heat source for cooking the produce conveyed through the oven. The conveying interior preferably comprises a rotating drum with a conveying spiral extending inwardly from an inner wall of the rotating drum. The rotating drum may further be sloped downward to facilitate progress of the produce through the oven, and the time spent in the oven may be controlled by controlling the rotating rate of the drum. The gas fired heat source may comprise a thermostatically controlled burner residing under the drum.