The invention relates to a process for the preparation of an expanded dairy product having the largest dimension of at least 1 cm, directly from a piece of seasoned cheese, without subjecting the seasoned cheese to grinding, which process consists in subjecting a piece of cheese obtained by cut from a wheel of hard cheese at a distance comprised between 1 mm and 2 cm, to a microwave oven treatment, followed by a quick cooling by air. The invention also relates to the expanded dairy product obtainable thereby.