Heat the oil in a pan. Sauté the onion and garlic for approx. 2 mins. Add the tomato, pepper, chilli and beans, pour in the red wine and water, season. Cover and simmer over a low heat for approx. 1 hr., puree. Mix in the chocolate, allow the bean puree to cool slightly.
Mix the coriander, oil and lemon juice into the bean puree, season. Serve the bean dip in a bowl, serve with nachos.