For the rice, use basmati, and cook with a pinch of saffron steeped in a few tablespoons of warm water along with a knob of butter. Place all the ingredients for the marinade in a bowl, add the chicken and toss until it is completely coated.
Cover and leave to marinate for at least two hours, or overnight in the fridge.
Heat a large casserole over a high heat and cook the chicken in batches, until it is cooked all the way through and has deep char marks. Baste the chicken with the melted butter and lemon juice while it cooks.
Remove from the pot and set aside once cooked.
For the sauce, add the butter to the casserole. When it has melted, add the lightly crushed cardamom pods and onions. Cook for eight minutes, until softened and slightly browned. Add the garlic, ginger and chilli and continue to cook for a further two minutes.
Stir through the garam masala, cumin, coriander, chilli powder and tomato puree.
Lower the heat and, stirring continuously, slowly add the cream and stir until it is well combined. Bring to a low simmer and season with sea salt to taste.
Add the chicken to the casserole, stir everything together and cook until the chicken is warmed through.
Serve the butter chicken with basmati rice and naan breads.