How do I prepare and cook celeriac, swede and turnip?

These are among the cheapest vegetables in a British winter and among the least used, almost entirely because the first cut is intimidating. The technique for getting into them is the same for all three and takes a minute once you know it.

Safety

Step by step

1. Make a flat base before anything else.Cut a slice off the bottom so the vegetable sits stable on the board and cannot roll. This is the single change that makes the job safe. A round, wax-coated swede rolling under a knife is how people cut themselves.
2. Cut the whole thing in half through the flat base.Stand it on the flat side and cut down with a large heavy knife, pressing through with the heel of the blade. For a very dense swede, rock the knife rather than forcing it, and keep your other hand clear of the line of travel. Two halves are far easier to handle than one sphere.
3. Take the skin off with a knife in downward strips.Sit each half cut-side down and slice the skin away following the curve, taking a few millimetres. Swede skin is thick and often waxed; celeriac skin is gnarled with soil trapped in the roots; turnip skin is thinner but still tougher than a potato's. A peeler is the wrong tool for all three.
4. Cook celeriac where you want a smooth, aromatic result.It has a celery-parsley flavour and a much lower starch content than potato. Best boiled and mashed (on its own or half and half with potato), blended into a silky soup with stock and cream, roasted in wedges, or shredded raw with mustard mayonnaise for remoulade. Put cut celeriac in acidulated water — it browns quickly.
5. Cook swede for mash, roasting and stews.Sweet, peppery and slightly earthy. Boil in chunks for 20–25 minutes and mash hard with plenty of butter, salt and white pepper — swede mash needs more seasoning than it looks like it should. It roasts well at 200°C for 40 minutes, and it holds its shape in a long braise better than potato.
6. Buy turnips small and cook them briefly.Young turnips the size of a golf ball or a small apple are sweet and mild; large ones turn hot, peppery and woody. Small ones need only quartering and 10–15 minutes glazed in butter and stock, or roasting. Very large turnips are best in a stew where the long cook softens the flavour.
7. Cut evenly and give them time.All three are dense and slow. Cut to a consistent 3–4 cm, start from cold water for boiling, and expect 20–30 minutes rather than the 15 a potato takes. Undercooked swede in particular is unpleasantly hard.

Tips

• Swede and turnip are the same word in different parts of Britain, which causes real confusion. In Scotland 'neeps' means swede; in much of England 'turnip' means the smaller white-and-purple root. Buy by appearance: swede is large, dense, yellow-fleshed and often waxed; turnip is smaller, white-fleshed and purple-shouldered.
• Celeriac remoulade — coarsely shredded raw celeriac in a mustardy mayonnaise — is worth knowing as a five-minute side that uses the vegetable raw and to its best advantage.
• All three are excellent in a mixed root mash with carrot and potato, and all three make good chips or roasted wedges.
• The waxy coating on a swede is food-grade and harmless, but you are taking the skin off anyway so it goes with it.

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