Sauté the onion for a few minutes until soft, before adding the minced beef.
Brown the beef quickly for a few minutes and then add spices and garlic. Stir for another minute
Add tomatoes and stock, and then stir in cocoa powder and molasses sugar if using
Bring to the boil and then transfer to a casserole dish in a preheated oven at 90 degrees C for 4 hours (or slow cooker) or 150 degrees C for 2 hours. Stir periodically and top up with a little more stock if needed.
Serve topped with coriander leaves and brown basmati rice