In a large pot, add onion, garlic and olive oil and saute over medium heat until onion starts to soften.

Add curry powder, garam masala, ginger and desired amount of chili powder then stir into onions so the spices get a little toast on them.

Add tomato sauce and chicken stock and let mixture simmer on low for about 6 minutes.

Add salt, sugar, cream and butter to mixture and bring to a boil again for 1 minute then reduce to a medium simmer.

In another non-stick skillet, add chicken that is sliced into bite sized chunks and season with a sprinkle of salt and garam masala. Cook through then add to simmering mixture. I like to cook the chicken separate because I find the chicken gets more tender when I do it this way. You can also add the raw chicken to the sauce mixture and cook it in the sauce if desired but chicken will get a little firmer.

Once chicken is added you can serve over rice or reduce sauce to desired thickness by simmering for a few more minutes.