Making your own from dried red chillies is relatively easy, but whether making or shopping, try to keep quantities small because although it lasts a long time, a little goes a very long way.

Harissa is properly served alongside couscous dishes, in which case each diner stirs it into the accompanying stew to suit personal taste.

You can serve tiny dabs of harissa as a side sauce for grilled and roast meats and poultry, or use it as a general flavour booster for stews and sauces. It can also be spread lightly on bread.

Buy a resealable tube if possible, otherwise store in a screw-top jar in the fridge, making sure it is kept covered with a thin layer of olive oil. Use within three months, or adhere to the manufacturer's best-before date.

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