Slow cooker butter chicken

Place cashews in a medium bowl and cover with cold water; stand for 30 minutes or until plump and pale in colour.

Meanwhile, place chicken, buttermilk and spices in a large bowl; stir well to coat chicken completely. Cover and refrigerate for 30 minutes.

Drain chicken; reserve marinade. Heat oil in a large frying pan over high heat. Cook chicken in batches for 3 minutes each side or until lightly golden. Transfer chicken to a 5-litre (20-cup) slow cooker. Wipe the pan clean.

Place onion in the same pan; cook, stirring, for 4 minutes or until starting to soften. Stir in tomato paste and reserved marinade. Cook for 2 minutes or until mixture comes to a simmer and is fragrant.

Transfer onion mixture to the cooker. Stir in sweet potato, carrot and stock. Cook, covered, on LOW for 4½ hours or HIGH for 2½ hours, or until chicken is falling off the bone and vegetables are tender.

Meanwhile, drain cashews; reserve ½ cup of the soaking liquid. Process cashews and reserved soaking liquid to a smooth paste (use a high-powered blender if you have one, as this will achieve a very smooth result). Set aside until needed.

Transfer ½ cup (125ml) of the curry sauce to a large jug; stir in cashew paste until smooth. Return curry sauce to cooker and stir to combine. Add the corn. Cook, uncovered, for a further 30 minutes on HIGH or until sauce thickens and coats the back of a wooden spoon. Stir in spinach until just beginning to wilt. Season.

To serve, divide butter chicken among bowls; scatter with chopped cashews. Serve with steamed basmati rice.