Aloha Steve, Just like you cook a turkey in.It is basically a
heating mantle with a seperate pan for cooking.The one I had,the
thermostat went to 500 degrees and yes,rectangular in shape(18 qts.
in volume).There is probably a lower tech solution,but this works
the same as a commercial unit,at a fraction of the cost.
Regards,
Christian Grunewald
Precision Modelmaking
Hawaii