Butter chicken originated in Delhi in the 50s, and is definitely not a dish for the calorie conscious. Extravagant amounts of butter and cream are combined with tandoori-style chicken in a mildly spiced tomato sauce to create a luxurious dish of murgh makhani.
Make the marinade
Combine all the marinade ingredients (except the lemon zest) in a bowl. Remove any skin and bones from the chicken and cut into bite-sized chunks. Stir the chicken into the marinade mixture and either cover the bowl with plastic film, or put the whole lot into a freezer bag - I prefer the bag method because you can easily squeeze the marinade around the meat.
Marinade the chicken
Place the marinade and chicken in the fridge and leave it overnight if you can. If you haven't allowed time for that (I always forget about overnight marinading), give it at least 3 hours.
Make the tomato sauce
Melt the butter on medium heat. Break the cinnamon into small pieces, crush the cardamoms, and add them, the cloves and the fenugreek seeds to the butter. Let them cook for a few minutes, add the ginger and garlic paste and cook for a few minutes more.
Then add the tomatoes. You might want to break down the tomatoes using a potato masher. Finely chop the almonds, add them to the sauce base and simmer for 20 minutes. At the end of this time, the butter should be separating out around the edge of the pan. This means the sauce is ready. If you want a smooth restaurant style sauce, whizz it in a blender and then pass it through a sieve, using the back of a spoon to extract as much liquid as possible.
Cook the chicken
While the sauce is cooking, you can get on with the chicken. Preheat your oven to 230°C (446°F). Thread lumps of chicken onto skewers and place them on a foil-lined baking sheet. Cook them for 20 minutes. If you can get some charring on the edges of the chicken, that's great.
Finish the butter chicken
Add any excess marinade to the sauce. When the chicken skewers are ready, use a fork to remove the chunks and add them to the sauce. Add the remaining garam masala, as many chilli flakes as you like, and most of the coriander, finely chopped. Taste the sauce - you might also want to add a pinch of salt.
Serve the butter chicken with naan or roti or pilau rice. Garnish with a sprinkling of chopped cilantro and the lemon zest.