Heat your pan, medium heat and add your butter.
Once melted add diced onion.
Cook onions until translucent and just starting to brown.
Add cayenne, coriander, paprika, cardamon, nutmeg and cumin, stir constantly for about 2 mins to allow the spices to toast.
Add chicken, salt & black pepper.
Cook chicken through over medium heat.
Add your ginger, tomato paste and cream, stir well.
Bring to a simmer and turn heat to low, stir occasionally.
Once sauce has thickened to your liking, season with salt & pepper.
Serve with rice of your choosing.