Ingredient

Liver

Liver from different animals varies enormously in strength and texture, far more than the muscle meat does. Calf's liver is delicate and expensive; ox liver is strong and coarse; lamb's liver sits between them and is what most British recipes assume.

The four you will meet

Calf's liver

Palest, finest-grained, mildest and most tender. The most expensive by a distance and the one worth pan-frying plain.

Lamb's liver

Mid-brown, moderately strong, tender. The British default and good value.

Pig's liver

Darker, stronger, slightly grainy and faintly bitter. Best in pâté, faggots and terrines rather than pan-fried.

Ox liver

Darkest, coarsest, strongest. Cheap, and it needs slow cooking or blending into something.

Chicken liver

Small, soft, mild and sweet. A different proposition entirely and treated separately.

Preparing a piece of liver

1. Peel off the fine outer membrane if it is still attached. Slide a thumbnail under an edge and it usually lifts away in one piece; left on, it contracts and curls the slice in the pan.
2. Cut out any tough tubes with a small sharp knife.
3. Slice across the grain, about a centimetre thick. Thick slices overcook outside before the middle warms; very thin ones go from pink to grey instantly.
4. For strong livers — pig and ox — soak in milk for an hour and pat dry. This genuinely moderates the flavour and does little for the mild ones.
5. Dust lightly in seasoned flour if you want a coating that browns fast and holds a sauce.
6. Dry the surface well before it hits the pan.

Cooking it

• Liver and onions, the British classic. Onions cooked slowly and thoroughly first, liver fried fast at the end, gravy from the pan.
• Fegato alla veneziana, calf's liver with onions cooked slowly in oil and finished with vinegar or white wine. The same idea, better executed.
• With bacon and sage, where the fat and the herb both cut the richness.
• In a pâté or terrine, where pig's liver is the right choice.
• Faggots, minced with pork and offal, wrapped in caul fat and baked in gravy.
• Sliced very thin and flash-fried for a salad with something sharp — capers, mustard, a lot of parsley.
• Never boiled or stewed long. It goes grey and grainy with no recovery.

Why it must stay pink

Liver is dense in protein and holds almost no fat or connective tissue. When the proteins set fully they contract and expel moisture, and there is nothing left to make up for it. The result is dry, chalky and metallic.

A properly cooked slice is browned on both faces and rosy in the middle, and it will still be faintly soft when pressed. It sets a little further while resting.

How thoroughly offal should be cooked is a food-safety question rather than only a culinary one, and current Food Standards Agency guidance is the thing to follow.

Common questions