This appliance comprises a pair of plates made of a material that conducts heat well which are heated electrically and are hinged to each other, each of these plates having a cooking surface, which two cooking surfaces can be brought toward each other by pivoting one plate onto the other in order to cook a food product which is clamped between them, the rear or non-cooking surface of each of these plates having a depression with a flat base whose area is large; in accordance with disclosure, a heating module whose shape is complementary to that of said depression is fitted into and fixed removably inside the latter, this module being provided with a shielded electric resistor capable of heating said plate and is supplied with electric current.