Turmeric.

Fresh khamin chan looks like a smaller, knobblier cousin of ginger, with thin brown skin and ringed joints. Cut it and the flesh is a startling deep orange. The smell is earthy and a little peppery, and the taste slightly bitter. It colours everything it touches, the curry, the rice, the chopping board and your fingers, so a lot of cooks wear gloves or use an old board for it.

Ways to use it

• Pound it into the paste for kaeng lueang, the sour yellow curry of the south, along with chilli, garlic and shrimp paste.
• Crush it with garlic and salt and rub it over fish or chicken before frying, as in pla tod khamin and kai tod khamin.
• Add a little to the paste for kua kling, the dry southern stir fry of minced meat.
• Grate a small piece into rice as it cooks for a golden colour.
• Slice thin and steep in hot water with lemongrass for a warm drink.

There's no need to peel young roots. Older ones can be scraped with the edge of a spoon.

Storing it

Keep the root dry and unwashed, and use it within a few days. Scrub it under running water with a clean brush right before cooking, because soil sits in the joints. A turmeric stain on a board or counter fades faster if you wash it off straight away.

Where it comes from

Grown to certified organic standards. The certificate for each lot is shown when you trace your pack.

Every pack will carry a lot code. Enter it on the Trace your pack page and you will see the farms in that lot, the harvest date and the certificate.