Heat the ghee in a pan and sauté onions until golden brown.
Marinate chicken breasts with garam masala, red chili paste or powder (adjust according to taste), salt and yogurt if using for at least 30 minutes as this helps tenderize the meat. Preheat a grill/skillet.
Grill until fully cooked.
In another pan, heat ghee separately over medium flame and sauté tomato puree with spices till oil separates on top of the masala (indicating readiness).
Add in marinated chicken pieces to this mixture.
Cook for around 10-15 minutes, or until sauce thickens slightly.
(Optional) For a richer taste and texture, add the chopped cream towards the end of cooking.
Simmer on low heat for few more minutes to blend all flavors together
Serve butter chicken with naan or rice.