Chop up chicken into cubes and place in a bowl.
Add salt and pepper, 1 tsp chilli powder and 1/2 tsp tumeric.
Mix together till all pieces are coated with the spices.
Add 2 tbsp butter into pan.
Once melted, add chicken and cook till all white on outside.
Remove chicken from pan.
To the same pan, add another 2 tbsp butter.
Add onion, garam marsala, remaining chilli powder, cumin, cayenne pepper, ginger, garlic, cinnamon stick and salt and pepper. Stir well.
Add in tomato sauce and stir.
Add in 1 cup water and 1 cup cream, stir.
Add the chicken back in and simmer for 10-15 minutes on low.
Turn off head and add 2 tbsp butter.
Serve with basmati rice and/or naan.