Butter chicken curry with green chilli and cashews

Ingredients

• 1.5 kilogram whole chicken, segmented into 8 pieces
• 1/3 cup tandoori paste
• 1/3 cup ghee (clarified butter)
• 2 centimetre ginger, peeled, grated
• 1 long green chilli, sliced, plus extra to serve
• 1 teaspoon garam masala
• 1 teaspoon ground cumin
• 1 teaspoon brown sugar
• 2 cup chicken stock
• 400 millilitre bottle tomato passata
• juice of 1 lemon
• 400 millilitre can coconut cream
• chopped coriander leaves, cashews, naan, basmati rice, mango chutney to serve