For the chicken marinade:

500 g (1.1 lbs) boneless chicken thighs or breasts, cubed

150 g (¾ cup) plain yogurt

1 tbsp lemon juice

2 tsp ground cumin

2 tsp ground coriander

1 tsp garam masala

1 tsp turmeric powder

1 tsp Kashmiri chili powder (or paprika)

1 tsp salt

2 garlic cloves, minced

1-inch ginger, grated

For the butter chicken sauce:

3 tbsp unsalted butter

2 tbsp vegetable oil

1 large onion, finely chopped

4 garlic cloves, minced

1-inch ginger, grated

2 tsp ground cumin

2 tsp garam masala

1 tsp ground coriander

1 tsp turmeric powder

1–2 tsp Kashmiri chili powder

400 g (14 oz) crushed tomatoes or puree

200 ml (¾ cup) heavy cream

100 ml (½ cup) chicken stock or water

2 tbsp tomato paste

2 tbsp sugar or honey

1 ½ tsp salt (to taste)

3 tbsp chopped fresh cilantro, garnish