Marinate chicken with lemon juice, chili powder and salt. Cover and rest for 20 minutes. Next add yogurt, kasuri methi, oil, turmeric, ginger garlic paste, coriander powder, cumin powder and garam masala powder.
Marinate and rest for a minimum of 30 minutes, or overnight for best results. Cover and refrigerate.
Optional – If using onion, sauté in 1 tablespoon oil until lightly golden, for 7 minutes. Cool down.
To a blender, add tomatoes, sautéed onions, cashews and water. Blend to a smooth puree. If you want you can also blend the cashews separately with water to a smooth cream.
Remove the chicken from the refrigerator, to bring it close to room temperature.
Melt butter in a pan & add all the whole spices – cinnamon, cloves and cardamoms.
When they begin to sizzle, stir in the ginger garlic paste & green chilies. Fry on a low heat, for a minute or 2, till it turns fragrant but not burnt.
Turn off the heat and stir in red chili powder, garam masala, cumin and coriander powder.
Stir in the tomato cashew puree. If it is not smooth, strain it to the pan.
Mix well and cover partially. Bring it to a boil on a medium high heat, reduce the heat to low or medium. Cook until the puree turns thick, keep stirring occasionally.
Pour hot water and simmer for 10 mins, until the sauce thickens & traces of fats are visible on top of the sauce. Remove the whole spices and discard at this stage.
Spread one tbsp. butter or ghee in a griddle/pan and heat it well. Place the marinated chicken pieces, spacing them a little apart.
Fry on a medium heat for 2 mins and turn them. Don’t burn and do not overcook. Cook till the chicken is just cooked and all the marinade dries up. It is not necessary to fully cook the chicken at this stage.
This way roast the chicken pieces in 2 to 3 batches, depending on the size of your skillet.
Add chicken to the butter chicken gravy. Pour more hot water (about ½ cup, not in the recipe) if the sauce is too thick. Cover and simmer for about 5 to 7 minutes till it becomes tender.
Stir in salt, sugar and kasuri methi. Taste test and optionally add more garam masala & another tablespoon butter for additional flavour (both are optional).
Turn off and stir in the heavy cream. Garnish Butter Chicken with chopped coriander leaves and some cream. Serve with Turmeric rice, steamed Basmati Rice, Butter naan or Cumin Rice.