Add garam masala, cumin, turmeric and ground coriander. Mix well and cook a few seconds, but do not allow to burn.
Add tomato sauce and stir to combine. Add Kashmiri chili and salt to taste. Let simmer for 10 to 15 minutes, stirring occasionally until sauce starts to thicken.
Add cream and brown sugar. Taste sauce and adjust seasonings as needed. If it is too spicy for your taste, you can add a little extra cream or yogurt.
Simmer as needed to achieve the desired consistency. Add back chicken and simmer a few minutes more to warm through.
Serve garnished with cilantro along side naan and raita.