800g boneless and skinless chicken

thighs, cut into bite-sized pieces
coriander leaves, finely sliced red onion, sliced green or red chilli, naan bread or basmati rice, and chutney, to serve
For the marinade
120g Greek yogurt
thumb-sized piece ginger

, grated
4-5 garlic cloves, crushed
1 tbsp vegetable oil
1 lemon

, juiced
3 tsp mild chilli powder
1 tsp ground cumin

½ tsp garam masala

½ tsp turmeric

For the sauce
1kg ripe vine or plum tomatoes

thumb-sized piece ginger

, peeled, half grated and half finely chopped
4 garlic cloves, crushed
4 green cardamom pods
2 cloves

1 bay leaf
1-2 tsp chilli powder
80g butter...