Kidneys are sometimes sold with a thick layer of fat left on them. Calf’s and lamb’s kidneys are sometimes roasted whole with the fat.
- If the kidney is encased in fat, snip the fat where it is attached to the core of the kidney and pull it away with your hands.
- Peel off the covering skin (membrane) and discard it.
- Cut the ducts from the center, without damaging the kidney.
- Calf’s, pig’s or beef kidneys are cut into cubes for cooking. (First make sure the ducts have been removed completely from the center.)