A device for cooking a starch-based food item is provided in which there is a drying cycle at a temperature below the gelatinization temperature and a cooking cycle at a temperature above the gelatinization temperature. The drying provides a relative weight drop by a first amount and the cooking provides a further relative weight drop. The weight is monitored during drying and cooking to provide feedback control of the duration of the drying and cooking times. The device and method make healthy food with reduced rapid digestible starch (RDS) and increased resistant starch (RS) content. In this way the glycemic index (GI) of a food item is reduced and the resistant starch is increased, which is beneficial to health especially for diabetes and obese groups.