Place the prepared chicken pieces in a mixing bowl. Add the lemon juice and salt and rub them well. Use a skewer or a fork to pierce the meat as you mix the seasoning. Set it aside for about 20 minutes.
Add minced ginger, garlic, ground cumin, paprika powder, chili powder, heavy cream and garam masala. Mix well until all the chicken pieces are covered with spices and cream. Cover the bowl and leave it in the refrigerator for at least six hours. The longer, the better for the spices to develop in the meat.
When ready to cook, put the meat on skewers and place them on a baking tray. Cook the chicken tikka in a grilled oven, ordinary oven, air fryer, or instant pot at 350°F/ 180°C. It takes approximately 12-15 minutes to grill the chicken, or it is cooked through and lightly browned.
For the masala:
Heat the oil on a lidded pan at medium-high heat. Once the oil is hot, fry the onion slices until golden brown.
Add the ginger and garlic. Stir-fry for about a minute until they release aroma.
Add coriander, turmeric, chili, and paprika powder. Stir fry for about 15 seconds before adding one tablespoon of plain yogurt.
Keep frying until the liquid is absorbed. Repeat this process of adding one tablespoon of yogurt until all yogurt is finished.
Chop two medium tomatoes and put them into the spices mixture. Cook for 3-4 minutes until the tomatoes turn soft and pulpy. Try mashing them with the back of a wooden spoon.
Then, add the chicken stock and salt to the mixture. Continue cooking at low heat and simmer for 15 minutes or until the sauce is thick.
Lastly, stir in the garam masala and check the flavors. Add more salt if needed.
Notes
Single cream can be used to replace heavy cream.
Kashmiri red chili powder gives a more vibrant color to the dish and has more flavor in its spiciness. You can substitute it with cayenne pepper powder if you don't have it.
If you like, you can omit the chicken stock and just use water to replace it.
Increase the salt if your chicken stock is unsalted. Do a taste check to ensure the saltiness is according to your liking.