SWEET POTATO

They were cultivating sweet potatoes in Central and South America for about 7000–8000 years before Columbus arrived. He thought they looked like yams and tasted like chestnuts, and shipped them back to Spain along with chillies and chocolate. Like ducks to water, sweet potatoes took to local conditions and thrived in the Mediterranean climate. This was just the beginning of their global conquest – sweet potatoes are now grown in more developing countries than any other root crop. Their big advantage over regular potatoes is that their skin does not develop green patches (see here ). They are easy to prepare – peel or scrub and roast, boil, steam, mash, add to stir-fries or use in place of pumpkin (squash) in desserts. Sweet potatoes are not as sweet as pumpkins, and are much starchier, so they will thicken a dish more if substituted.

WHAT TO LOOK FOR

Look for sweet potatoes with firm skin that are free from blemishes, cracks and soft spots. Choosing ones that are similar in size makes it easier to achieve even cooking. We like the small to medium ones with plump middles and tapered ends.

HOW TO STORE THEM

They are good keepers, like potatoes, and should be stored in a cool, dark spot. Don’t store them in the fridge because this will encourage softening and sprouting.

WHAT’S IN THEM?

A small raw orange-fleshed sweet potato (about 200 g/7 oz) has about 585 kilojoules (140 calories), 4 g protein, no fat, 28 g carbs (11 g sugars, 17 g starches), 6 g fibre, 20 mg sodium, 490 mg potassium and a moderate GI (61) when cooked; the GL is medium (17). Note that purple skinned sweet potatoes with white flesh have a high GI (75).

WHAT ELSE?

Sweet potatoes come in a variety of colours, shapes and sizes. It’s the orange-fleshed sweet potato that we like to roast and use in recipes for its colour and flavour.

HERO RECIPES

Pan-roasted sweet potato and beetroot with grapefruit glaze (here )

Sweet potato, quinoa, spinach and red lentil burgers with tahini-mint yoghurt (here )