Embodiments herein relate to a food preparation device (100). The food preparation device (100) comprises a bottom unit (110A) for accommodating a first piece of bread (140A)； a top unit (110B) for accommodating a second piece of bread (140B). The bottom and the top units each comprising a horizontally flat edge (120) along the circumference of the bottom unit respectively the circumference of the top unit. The flat edge (121) of the first piece of bread and the flat edge (121) of the second piece of bread are provided with an edible and organic adhesive layer, for enabling the sealing together of the two pieces of bread along the flat edges (121) when moving the tope unit from the open position to a closing position, thereby avoiding leakage before consumption.
