Cube chicken to 1 to 1½ inch pieces. Add them to a mixing bowl. Make sure there is no excess moisture in your chicken.
Add red chilli powder, garam masala, cumin powder, coriander powder, turmeric, salt, lemon juice, oil, ginger garlic paste, yogurt and kasuri methi. Skip the lemon juice if your yogurt is sour
Mix well. Cover with a cling wrap and refrigerate for minimum of 8 hours and upto 48 hours. If you are in a rush, you may cut down to 3 hours.
Make Tikka Sauce:
Heat oil or ghee in a pot or pan. Add onions and sprinkle 1 teaspoon salt. Sauteuntil deep golden.
Add ginger garlic paste and green chilli. Saute until aromatic, for 40 to 60seconds.
Reduce the heat to low. Add red chilli powder, coriander powder, garam masalaand cumin powder. Stir well quickly.
Pour tomato puree and cook on a medium high heat until the onion tomato masala becomes really thick and begins to leave the sides of the pan. It also turns fragrant
Pour 2 cups of hot water and cover. Simmer until thick, yet of pouring consistency.
How to Make Chicken Tikka Masala:
Grill in Oven: While the gravy simmers, thread the chicken to the metalskewers or soaked bamboo skewers and place them in a prepared tray. Bake them in a preheated oven at 460 F or 240 C for 9 to 10 mins.
Turn them to the other side with a tong and grill then for another 9 to 10 mins. To char the chicken, broil for 2 to 3 mins or until slightly charred.
In a Skillet: Pour 1 tbsp oil to a skillet and heat it well. Place the chicken tikka one by one, spacing them apart.
Cook on a medium high heat for 3 mins, turn them to the other side with a tong and cook for another 3 mins, until charred and not essentially fully cooked. Remove to a plate and Cook in batches.
Turn off and garnish with cream and coriander leaves. Serve chicken tikka masala with Butter Naan, or rice.