Abstract: The present application relates to a method of cooking cereal grains comprising a first step (S1) of subjecting an initial volume of cereal grains (3) to hot air in a vessel (2) having air temperature between 150 to 250 degrees Centrigrade for between 30 to 180 second; and a second step (S2) of subjecting the expanded cereal grains (3) to boiling water and/or steam. The second step (S2) is performed subsequent to the first step (S1) whilst the expanded cereal grains remain in the vessel (2). A device for cooking cereal grains (3) is also disclosed. The invention increases the overall volume of the cooked cereal grains compared to conventional cooking methods which results in cereal grains having a lower energy density.