Heat a pan with oil and add onions. Stir fry until deep golden to light brown.
Add ginger garlic paste and saute for a minute.
Reduce the heat to lowest. Stir in Kashmiri red chilli powder, turmeric, garam masala, coriander powder, cumin powder and salt.
Immediately pour 3 to 4 tablespoons water and cook until the water evaporates.
Add the tomatoes and saute on a medium high heat for 3 mins. Cover and simmer until the tomatoes break down to a mush.
Reduce the heat and stir in the nut paste (optional) and cook until you see traces of oil on the top or sides of the pan. (If using cream wait until the last step)
Pour water and bring it to a rolling boil. Cover and simmer until the gravy turns thick and the onions are softened.
Add sugar and kasuri methi. Taste test and add more salt if you want. Mix and turn off. Your tikka masala is ready.
For this recipe, it is essential to cool down the sauce a bit before cooking your shrimp with the sauce. Else your shrimp will be bland.
Optional - If you want a smooth sauce, cool this and blend to a smooth gravy, adding more water if required. If you want some texture in the gravy, blend only a part of it.
Mix together shrimp, lemon juice, red chilli powder, salt, garam masala, coriander powder, cumin powder, turmeric, garlic powder (optional) and kasuri methi. Rest aside for 5 to 8 mins.
Add 1 tablespoon oil or ghee to a wide skillet or pan. Spread the oil and begin to heat on a medium heat.
When the pan is medium hot, begin to layer the marinated shrimp and cook just for a minute. Quickly with a tong, turn them to the other side and cook for another minute. Do not burn.
Immediately pour the cooled or warm tikka masala to the pan. Stir and cook on a low heat just until the shrimp transform to a “C” shape, which means they are cooked. It takes only about 2 to 3 mins depending on the size of your shrimps. Do not overcook.
Take the pan off the stove and stir in cream if using. Keep covered until served,
Turn off and garnish shrimp tikka masala with cream and chopped coriander leaves.