For the Chicken:

In a medium bowl, make the marinade by combining the yogurt, Tikka Masala, cayenne, garlic, ginger, lemon juice and salt. Whisk to combine and set aside. Cut each chicken breast into quarters and place the pieces in the marinade.Put the marinating chicken in the refrigerator and allow to sit between 2 - 4 hours. Don't over marinate the chicken, as the acid in the yogurt and lemon juice will change the texture of the chicken, making it mealy and dry if marinated for too long. 

Line a sheet tray with heavy duty aluminum foil and preheat the broiler on high with the rack set 6" below the broiler element. Remove the chicken pieces, allowing the excess marinade to drip back into the bowl. Place them on the prepared sheet pan and broil until the meat is charred and blistered on the surface, about 8 minutes. The chicken will only be par cooked — this is ok. Transfer the charred chicken to a cutting board and let it rest for 10 minutes.

Chop the chicken into bite-sized pieces and set aside.

For the Tikka Masala:

Heat the butter in a large Dutch oven or heavy bottomed pot, over medium-high heat until melted. Add the spices and stir for about 10 seconds, until fragrant. Add the onions, garlic, and ginger. Cook, stirring frequently for about 10 minutes until the vegetables become soft and translucent. Add the tomatoes, lemon juice and half of the cilantro. Continue cooking, stirring to scrape any brown bits from the bottom of the pan. Cover and simmer on low for 10 minutes. Turn off the heat under the pot and puree the sauce using an immersion blender.

Add the cream to the pureed sauce, then add the chicken. Bring to a simmer over medium heat and cook, stirring frequently, until the chicken is fully cooked about 5-10 minutes. Season to taste with additional salt. Serve over rice along with the remaining cilantro and sliced lemons for garnish.