What: A macadamia-like nut used as a thickening agent in dishes like curries , chilli pastes and general stir fries once cooked and finely ground

How: Grown in the tropical climates of South East Asia, it is used a lot in Malaysian and Indonesian cooking.

To use: The outer shell is charred before it is cracked to reach the kernel. You can buy it in small packs from some Chinese / Thai / Asian supermarkets. Sometimes this comes ready ground. If you cannot find them then macadamia nuts can be used as a substitute. They will generally give a similar texture to a dish but the taste will not be quite as strong as the real thing.