Preheat the oven to 170ºC, fan 160ºC, gas 3. In a large ovenproof casserole dish, heat half the oil over a medium heat. Brown the pork on all sides – preferably in a couple of batches – then transfer to a bowl.
Heat the remaining oil in the casserole dish, add the onions and cook for 5 minutes. Add the garlic and smoked paprika, then cook for a further 30 seconds.
Add the chopped tomatoes and black-eye beans with 300ml boiling water and the browned pork, stir well and bring to a simmer. Cover and cook in the oven for 1½ hours, stirring occasionally.
Remove the casserole from the oven and stir in the chocolate until it has melted. Serve with the basmati rice and avocado slices.