Potato

You can leave the skin on if it is clean and unblemished; scrub it well under running water. Peeling is useful for smooth mash or if the skin is green, damaged or heavily sprouted.

Parboil peeled chunks for about 8–10 minutes, drain and shake them in the pan to roughen the edges. Roast in a preheated tray with hot oil at 200 °C fan (220 °C conventional) for 45–60 minutes, turning once.

Push a small, sharp knife into the thickest part: it should slide in easily without the potato breaking apart. Small boiled potatoes may take 12–15 minutes; larger ones can need 20 minutes or more.

Keep them in a cool, dark, dry, well-ventilated place, in a paper or hessian sack rather than a sealed plastic bag. Keep them away from onions, and refrigerate cooked potatoes promptly.

Raw potatoes turn watery and discoloured in the freezer. For better results, blanch cut chips or cubes for 2–3 minutes, cool and dry them thoroughly, then freeze; you can cook them from frozen.

Potatoes work in shepherd’s pie, potato salad, tortilla española, gratin dauphinois and fish pie. For fluffy mash, use a floury potato and mash it while hot with warm milk and butter.

Small sprouts can be cut out generously if the potato is still firm and otherwise looks sound. Throw away potatoes that are green, badly sprouted, shrivelled or bitter; do not taste them to check.