In a large saucepan of 2 cups water, cook rice according to package instructions; set aside.
Season chicken with 1 teaspoon salt and 1/2 teaspoon pepper.
Heat vegetable oil in a large stockpot or Dutch oven over medium heat. Add chicken and onion to the stockpot and cook until golden, about 4-5 minutes.
Stir in tomato paste, garlic, ginger, garam masala, chili powder and turmeric until fragrant, about 1 minute.
Stir in tomato sauce and chicken stock; season with salt and pepper, to taste. Bring to a boil; reduce heat and simmer, stirring occasionally, until reduced and slightly thickened, about 10 minutes.
Stir in heavy cream until heated through, about 1 minute.
Serve immediately with rice, garnished with cilantro, if desired.
Notes
Use chicken thighs. Chicken breasts are great as a leaner protein source, but chicken thighs will be more tender and juicier due to its higher fat content.
Tomato paste adds so much flavor. Tomato paste is a key ingredient in chicken tikka masala, adding body and richness in small amounts without adding too much liquid to the dish. Opt for tomato paste in a tube, using up only what you need at a time without having to open up a whole can.
Heavy cream will add ultra-richness. For that restaurant-quality richness, use heavy cream, adding at the very end and pouring very slowly to prevent curdling. Half-and-half can certainly be used instead to lower calorie and fat intake but it can curdle easily and result in a thinner, less authentic sauce.
Make it dairy-free. For a dairy-free version, swap out the heavy cream for coconut milk.
Serve with naan. Serve with all the naan for dipping, sopping and dunking!