A thermally efficient, low voltage, portable convection/conduction cooking oven that is an improvement of combination conduction/convection ovens, portable or permanently affixed in place. The oven contains a low thermal mass conductive cooking slab 6 heated by lower elements 17. The oven utilizes convective cooking by moving air with fan 10 across upper elements 9. The oven successfully utilizes 110-volt service, energizing upper elements 9 and lower elements 17 with a cumulative draw of no more than 1550 watts and 13.5 steady state amps while cooking foods in one fourth to one third the time of conventional ovens. The low thermal mass conductive cooking slab temperature is maintained optimally stable by means of lower heating elements 17 remaining energized throughout the conductive cooking process. The oven utilizes a unique grouping of thermally efficient improvements. These improvements produce in synergy a low profile, lightweight oven with exceptional preheating times, cooking limes and end product food quality.