Slice the duck or goose skin in square inch parts and put them in a flat pan with a heavy bottom
Add a half cup of water and heat the pan on medium heat
Now and then turn or stir the skin pieces. Continue with this process, until all the water is evaporated/cooked off. At that time continue to heat for a while and then poor the oil contents over a fine mesh sieve in a jar, keeping the skin pieces separate
Let the oil cool down and thereafter place the very light yellow colored molten duck fat in the refrigerator
Meanwhile continue to heat what remains of the skin pieces at a slightly higher heat: more, darker fat will be rendered, which can also be used, but has some smell and the remaining crisp ‘fritons de canard’ are delicious when lightly salted. The whole process takes a full hour.