Ingredient

Kidney

Kidney has a reputation for tasting of ammonia, and it is largely deserved when the organ has not been prepared. Trimmed, cored and briefly soaked, a lamb's kidney is mild, mineral and quite delicate — and it cooks in about three minutes.

Where the smell comes from

Kidneys filter urine, and traces remain in the tubules at the centre of the organ. That white or pale core is the source of the ammoniacal smell, and removing it removes most of the problem.

The rest is freshness. Kidneys deteriorate quickly and a strong smell in a fresh, well-trimmed kidney is unusual. A short soak in cold water, salted water or milk deals with what remains.

Ox kidney is the strongest and benefits most; lamb's kidney from a good butcher often needs almost nothing beyond coring.

Preparing lamb's kidneys

1. Peel off the fine outer membrane if it is still on. It lifts away easily.
2. Halve each kidney lengthways through the indentation.
3. Cut out the pale white core with a small sharp knife or a pair of kitchen scissors, taking a little more than looks necessary.
4. Soak the halves in cold salted water or milk for twenty to thirty minutes.
5. Rinse, drain and dry thoroughly.
6. Cook them fast in a very hot pan — two to three minutes total for halves. They should be browned outside and pink within.
7. Rest for a minute. Overcooked kidney goes rubbery and bitter and does not recover.

The kinds

Lamb's kidney

Small, smooth, single-lobed. Mildest and most tender. The one for devilled kidneys and quick pan dishes.

Veal kidney

Multi-lobed and knobbly, delicate and expensive. Highly regarded in French cooking.

Ox kidney

Large, multi-lobed, strong and firm. For steak and kidney pudding and pie, where long cooking suits it.

Pig's kidney

Single-lobed like lamb's but larger and stronger. Soak it properly.

Suet around the kidney

The hard white fat surrounding an ox or veal kidney is the source of proper suet, and is worth asking for.

What to make

• Devilled kidneys, on toast — fried fast, deglazed with Worcestershire sauce, mustard, cayenne and a splash of stock. A great British breakfast.
• Steak and kidney pudding or pie, using ox kidney, where hours of cooking suit the stronger organ.
• Rognons à la moutarde, sliced and served in a mustard cream sauce.
• Grilled on a skewer with bacon, in a mixed grill.
• Sautéed with sherry and shallots, on toast or with rice.
• In a pilaf with warm spice.
• Not stewed for an hour and a half unless it is ox kidney. Lamb's kidney goes rubbery.

Beef, veal and pig kidneys, which are not the same job

Lamb's kidneys are the ones to start with. The others behave differently enough to matter.

Lamb

Small, mild, tender. Grill or fry fast, or split for a mixed grill. The default.

Veal

The prize. Large, lobed, delicate, and expensive. Roast whole in its own fat, or slice and sauté briefly.

Pig

Stronger and firmer. Soak in milk or acidulated water first, then cook fast or braise long. Nothing in between.

Beef (ox)

The strongest and toughest, and the one for steak and kidney pudding. It needs long slow cooking and repays it.

The rule that spans them

Fast and pink, or slow and soft. The middle is where kidney turns to rubber.

Suet

The hard fat around a beef kidney, and the traditional pastry fat. A different product from the kidney itself.

Common questions