Preheat the slow cooker if necessary; see the manufacturer's instructions. Heat the butter in a large frying pan, add the chicken and fry on both sides until browned but not cooked through. Lift out of the pan with a slotted spoon and transfer to the slow cooker pot.
Add the onion, garlic and ginger to the pan and fry for 2–3 minutes, then stir in the curry paste and cook for 1 minute. Stir in the ground almonds, stock and salt and pepper and bring to the boil.
Pour the sauce over the chicken. Cover with the lid and cook on low for 6–7 hours or until the chicken is cooked through.
Stir in the cream and chopped coriander, replace the lid and cook, still on low, for 15 minutes. Slice the chicken. Spoon on to rice-lined plates and sprinkle with the almonds.