the invention relates to a system and method for the immersion cooking / cooling of food in diffused forced convection . the inventive system comprises : a tank for housing the food to be cooked / cooled , filling / emptying means for filling the vessel with a cooking or cooling liquid and emptying same , and heating means for heating the liquid . the tank comprises a lower region and an upper region , and circulation means which are intended : to collect liquid from the lower region by means of various outlets in a first lower side wall and to introduce said liquid into the upper region through various inlets in a first upper side wall , and to collect liquid from the upper region by means of various outlets in a second upper side wall and to introduce said liquid into the lower region through various inlets in a second lower side wall , thereby generating diffused forced convection in a turbulent flow .