A beef kidney is not a solid piece of meat. It is one central piece of flesh surrounded by little lobes of flesh.
Butchers trim off the blood vessels, the pizzle cord, and the ureter before sale. Each beef kidney after this trimming will weigh about 500 g (around a pound.)
Beef kidney needs slow cooking to tenderize it, either braising on its own or chopped up and put into a stew, or in the classic meat sauce for Steak and Kidney Pie or Pudding.
Beef kidney is stronger tasting and tougher than veal or lamb kidney.
“Ox kidney can take far more cooking than other kinds. Its chief duty is to give a good rich flavour, as it does in good old steak and kidney pie or pudding.” Dickson Wright, Clarissa and Jennifer Paterson. Two Fat Ladies Obsessions. London: Random House. 1999. Page 107.
Trim off the outer membrane, if the butcher hasn’t already. Then, cut the kidney in half lengthwise. In the centre, you will see a white piece of fat — extract and discard this.
Before using, soak the kidney for an hour in something acidic, such as buttermilk or water with some vinegar or lemon juice in it. This will help to make the taste a bit milder, by leeching uric acid out of it.
|↑1||Dickson Wright, Clarissa and Jennifer Paterson. Two Fat Ladies Obsessions. London: Random House. 1999. Page 107.|