1.Heat half the oil in a 6-litre (24-cup) pressure cooker; cook lamb, in batches, until browned. Remove from cooker.
2.Heat remaining oil in cooker; cook onion, garlic and chilli, stirring, until onion softens. Add spice; cook, stirring, until fragrant. Return lamb to cooker with tomatoes and coconut milk; secure lid. Bring cooker to high pressure. Reduce heat to stabilise pressure; cook 25 minutes.
3.Release pressure using the quick release method; remove lid. Stir in ground nuts; season to taste. Serve curry sprinkled with chopped nuts and coriander.
If you have an electric pressure cooker you won’t need to reduce the heat to stabilise pressure, your cooker will automatically stabilise itself. Always check the manufacturer’s instructions before using. You will need to blend or process ¾ cup (100g) roasted unsalted macadamia nuts for enough ground nuts for this recipe. This recipe is not suitable to freeze. Quick release method: Each time the lid is removed from the cooker, the pressure must be released quickly first. Use tongs (steam can burn your fingers) to turn the pressure valve on top of the cooker to open the valve and release the steam. We use this method when adding ingredients and when checking the food toward the end of cooking time.