Mix the flour, paprika, cayenne and cumin seeds. Toss the steak in this mixture - you may find it easier to put the lot in a large, sealed plastic bag and shake it all together.
Heat a little oil in a large pan and fry the steak in batches until it browns all over. Tip onto a plate.
Add a little more oil to the pan, and then fry the onions, garlic and chillies until the onions brown. Add the vinegar and bubble to a glaze. Do the same with the red wine. Add the tomato purée and cook for 2 minutes, then add the chopped tomatoes and cook for about 5 minutes or until the mixture has reduced by half.
Add the stock and beef and cook gently for 1 hour 30 minutes or until the meat is tender.
Add the chocolate and beans and heat through the beans. The chocolate will melt into the sauce. Add salt if needed.
Mix the crème fraîche with the coriander and season.
Serve with the chilli and mixed wild and basmati rice.