Score the duck skin, in a criss-cross pattern. Partially cut the duck breasts in half lengthwise. Apply an Espelette pepper marinade, with a brush, on the top of the duck skin.
Pack your duck in conservation (freezing bags) and let stand at least 8 hours in the refrigerator.
Take your breasts out of the fridge 15 minutes before serving Bake the duck on a hot griddle (250°). Let it cook 3 minutes, each side, until the meat turns pink. If necessary leave it a bit longer on the griddel.The meat has to be warm and pink.