Prepare onions, garlic and chicken and set aside separately. Dice the red pepper and add to a medium sized bowl with spice mixture.
In your skillet or dutch oven melt 2 tablespoons of butter over medium high heat.
Add chicken pieces and cook until no longer pink stirring only when needed so the chicken gets a nice caramel colour - approximately 5-7 minutes. Remove chicken and set aside.
In the same pan melt the remaining 2 tablespoons of butter. Saute onions for approximately 5 minutes until translucent and soft. Add garlic and cook stirring often for an additional 2 minutes.
Add contents from the medium sized bowl - red pepper, ginger, chili powder, turmeric and cinnamon. Cook another 2 minutes.
Add tomatoes, tomato paste, brown sugar, salt and pepper. If you would like to try pureeing your sauce do it at this point.
Add reserved Chicken, cover and simmer for 10 minutes.
Combine cream and yogurt into a small bowl or measuring cup. Tempering the cream and yogurt before adding it to the hot sauce will prevent it from separating. Add a scoop of the hot sauce to the cream and yogurt mix, stir then repeat with another scoop, then slowly add it all to your large saucepan.
Add cream and yogurt and stir. At this point you can transport home and refrigerate until dinner time. Heat through with the lid on just before dinner. Do not bring to a boil.
Stir in cilantro or sprinkle on top. Serve over basmati rice or with naan.Note: For taking home and reheating stop at step 6 - add the cream and yogurt but do not reheat on the stove until 15 minutes before dinner.