Heat 2 tablespoons of oil in a large pan over medium-high heat.
Fry diced beef steak in batches until browned and set aside.
Brown the beef mince in another tablespoon of oil and set aside with the steak.
Sauté the onions and celery in the remaining oil until softened.
Stir in the chillies, chilli flakes, powder, and oregano and cook for 2 minutes.
Add beef, sugar, tomatoes, stock, and beans to the pan.
Simmer the mixture covered on low heat or in a 140°C oven for 2 to 3 hours.
Season with salt and pepper and melt in the chocolate and coriander.
Serve over rice with a dollop of soured cream and spring onions.