An oven operable for cooking at both atmospheric and sub-atmospheric pressure, and a method of cooking are disclosed. The oven comprises a housing, defining a chassis comprising a cavity capable of receiving a food package. Moreover, the oven comprises at least one heating element, a gas outlet connectable to a vacuum source. The oven further has a maximum weight capacity for the food product and wherein the chassis is arranged to have a total heat capacity in the range of 1.5-3.0 times that of a heat capacity of water having the same weight as the maximum weight capacity of the oven. Hereby a simple and cost-efficient oven is presented, that is capable of heating a food product while the food product is kept in a sub-atmospheric pressure inside the oven.
