1. For the marinade, mix all of the ingredients together and coat prawns. Leave to one side for 10 minutes.
2. Pre heat the oven to 220°C cook the prawns for 8 to 10 minutes.
3. For the sauce, place all of the ingredients (apart from the butter) into a pan, cook for 10 minutes on a medium heat. With a stick blender, blitz to form a tomato broth. Return to the pan and cook for a further 15 minutes until it thickens. Now whisk in the butter and simmer for a further 5 minutes.
4. For the naan, mix all of the ingredients together and knead lightly to make a soft dough. Roll out on a floured surface into 20cm oval shapes. Heat a non stick fry pan and dry fry the naan. Place onto a baking tray, brush with butter, sprinkle with the nigella seeds and grill until crispy.
5. To finish the curry, add the prawns and serve with the naan.