1. First let us marinate the chicken.  Wash and cut the boneless chicken breasts into 2 inch cubes.
2. To a mixing bowl, add the chicken pieces and all the ingredients mentioned in "For Marination" list.  Combine all the ingredients together and mix well by applying the marinade to the chicken pieces.  Close this bowl and leave it in the refrigerator for 2 hours or more.
3. After the chicken gets marinated and when it is time to make the gravy, keep the marinated chicken out from the freezer.
4. Now let us start preparing the pan-fried chicken tikkas/kebabs:  Heat a kadai/wok and add 2 teaspoon oil. Once the oil is heated, add 2 tablespoons of butter.  After butter gets melted, add the marinated chicken pieces and fry in batches till they are cooked.
5. Add more butter if needed while frying. After frying remove and keep them aside.
6. Now start preparing the tomato gravy: Boil the tomatoes for 10 minutes in 1 cup water and switch off the gas. After cooling, add this to a mixer along with chopped onion and grind to a thin puree.
7. Heat the same pan in which the chicken tikkas were fried.
8. Add 1  teaspoon oil and 2 tablespoons of butter. After the butter melts, add ginger and green chilies and saute for 2 minutes.
9. Add the spice powders (turmeric powder, red chili powder, cumin powder, and coriander powder) one by one and saute till they mix well and are aromatic.
10. Now pour the tomato and onion puree and mix well with spices.
11. Simmer on low flame till oil rises to the surface of the gravy and the color of the gravy changes. Add the chicken tikka pieces and mix well.
12. Add ½ teaspoon sugar and mix well.
13. Simmer the gravy for 10 minutes. Now add fresh cream and tandoori mayo, mix and simmer for 5 minutes.
14. Adjust salt to taste. Garnish with cream, a knob of butter, and coriander leaves.

Enjoy your meal!