I just tried this today. It turned out absolutely delicious....just like the restaurant version. This is an amalgamation of several different recipes I found online. Its a little time consuming but very worth it, especially for guests.
4 bone-in chicken breasts (can use boneless but the bone helps the chicken stay moist), Approx 2 lbs
To marinate chicken:
Shan tandoori chicken masala (4-5 tbsp)
4 tbsp yogurt
2 tbsp ginger-garlic paste (I used fresh ginger/garlic crushed in the food processor)
Juice of 1 lime
Mix the above ingredients with the chicken and set aside in the fridge for a few hours (or overnight). Grill chicken until jut cooked (do not overcook). Set aside to cool completely. When cooled, cut into bite sized chunks for curry.
3 green cardamoms, lightly crushed
6-8 whole black peppercorns
1" stick of cinnamon
2 bay leaves
2 tsp coriander pdr
1 tsp cumin pdr
1.5-2 tsp red chili pdr (depending on your spice level)
1/4 tsp turmeric pdr
3 tbsp kasuri methi
1 tsp cumin seeds
1/2 tsp garam masala
1 large onion, chopped finely
2 tsp ginger-garlic paste (I used fresh)
2 tsp cashew butter or almond butter (You can also use 1/4 cup or so of nuts crushed in the food processor)
3/4 cup half and half
1/4 cup ketchup
1 tsp sugar
Salt to taste
3 tbsp butter
1 tsp oil
In a large pan, melt the butter and oil. When hot, add whole cumin seeds until sizzling. Now add chopped onion and saute until the onion is soft. Add ginger-garlic paste and saute for 2 minutes. Now add cloves, bay leaves, pepper, cinnamon and cardamom. Saute another 2 minutes taking care that the spices don't burn. Add coriander pdr, cumin pdr, red chili pdr, turmeric, and 2 tbsp kasuri methi (rubbed between the palm of your hands). If the mixture looks too dry and like it might burn, add a little oil or a little water and stir. Saute until the raw smell of spices disappears. Now add 2 chopped tomatoes and saute until the tomatoes are soft and the mixture starts forming a paste. Once you can see oil oozing out of the mixture, add about 4-6 cups of water to make a gravy. Add ketchup and sugar and cook mixture until slightly thickened.
Remove cinnamon stick and bay leaves and puree mixture with an immersion blender or when cool, puree in the blender until a smooth sauce is obtained. Return to pan and cook until the curry is thickened. Add grilled chicken pieces and half and half. and simmer on low for 5-10 minutes. Add remaining 1 tbsp crushed kasuri methi along with 1/2 tsp garam masala. Stir and remove from heat.