GRIDDLE: do not defrost before cooking. Preheat the griddle on maximum power or below, according to taste. One the griddle is hot, coat a small amount of oil on the surface and put the burgers on it. Cook for 2 to 2 1/2 minutes on each side..
OVEN: do not defrost before cooking. Preheat the oven 200º. Put the burgers onto a baking paper or directly on an oiled tray. Bake for 14-15 minutes with heat on both sides and fan on; turn upside down halfway through.