A cooking utensil includes a base (3) doubled underneath via an insert (1a) made from a hard material with openings (7) crossing the insert for the fixing thereof to the base. At least some of the openings are in the form of elongated slots (31a) individually defining over the length thereof, a global arched form with opposing end portions either leading to the centre of the insert or to the external periphery (10a) of the insert.