Japanese sweet potato.

The Japanese type of sweet potato has a dark purple-red skin and creamy, pale yellow flesh. Raw it's firm and starchy. Roast it slowly and it turns sweet, dense and a little fluffy, with sticky caramel at the ends where the juice leaks out. It needs nothing added, which is why it's become a common snack, eaten warm straight from the oven or steamer.

Ways to use it

• Roast whole, in the skin, at about 200 degrees Celsius until a knife slides in with no resistance. Thicker roots take close to an hour.
• Steam chunks and eat them plain, or mash them with a little butter or coconut milk.
• Simmer cubes in ginger syrup for man tom khing, a simple warm dessert.
• Cook pieces in sweetened coconut milk with a pinch of salt.
• Cut into wedges, toss with oil and bake until the edges brown.

The skin is thin and fine to eat once cooked, so most people leave it on.

Storing it

Sweet potatoes don't like the fridge. The cold spoils their texture, and they keep better somewhere cool, dry and airy, out of direct sun. Kept that way they last longer than most fresh vegetables, but check them now and then and use any that start to soften. Scrub them under running water just before cooking.

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.