Step 1

Trim the fat from the chicken thighs. Cube the chicken into 1-inch pieces.

Step 2

In a large bowl, mix together the items for the marinade - the dahi, lemon juice, ginger garlic paste, finely chopped green chilis, garam masala, turmeric, ground cumin, kashmiri chili powder, and salt. Once the marinade is ready, add the chicken into the bowl and toss so that it's fully coated.

Step 3

Cover the chicken with plastic wrap and marinate for a minimum of 30 minutes, up to 24 hours.

Step 4

Crush the green cardamom pods in a mortar and pestle or under the flat of a knife. Remove the black seeds inside the pod and discard the green part.

Step 5

Melt two tablespoons of butter in a pot on medium heat. Add the star anise, black cardamom, seeds from the green cardamom pods, cinnamon stick, and cumin seeds and allow the flavor to infuse with the butter for a minute.

Step 6

Add the chopped onions and ginger garlic paste into the butter. Sauté until the onions start to brown.

Step 7

Add the ground spices - the garam masala, coriander, cloves, and kashmiri chili powder. Give everything a good stir and let it cook for 1 minute so the spices can bloom in the butter. Don't let them sit for longer, otherwise the spices will burn.

Step 8

Stir in the tomato paste, canned crushed tomatoes, cashews (optional), sugar, and salt to taste.

Step 9

Switch the stove to low to medium heat, and allow the sauce to simmer. It'll start to thicken and darken significantly. This can take 5-10 minutes. The fat will start to release on the sides and form little pools. Switch the heat off.

Step 10

While the sauce is simmering in the step above, heat the cast iron skillet on high heat. Add a tablespoon of ghee or neutral oil in the pan and add in the marinated chicken. Cook on each side for 3-4 minutes until it reaches an internal temperature of 165 ºF and the chicken has browned. Set aside once done.

Step 11

Remove and discard the black cardamom pod, star anise, and cinnamon stick. Transfer the contents of the pot into a blender along with the rest of the butter. Blend the sauce until it's completely smooth. If it's too thick, add a tablespoon of water at a time. Add up to a 1/2 cup of hot water based off of preference if you’d like a looser curry.

Step 12

Transfer the sauce back into the pan and bring it back to a soft simmer. Add the chicken with all of the juices and spices into the pan. Stir to coat and simmer for an additional 5 minutes, until the fat begins to separate again.

Step 13

Slowly pour in the heavy cream while stirring. Continue to simmer for 2-3 minutes until the sauce is thick and creamy. This is a great point to taste and adjust for spices.

Step 14

Remove from heat and finish off the sauce with a pinch of kasuri methi.

Step 15

Garnish the butter chicken with heavy cream, cilantro, and finely diced red onions. Serve hot with rice or garlic naan.