Use a sharp knife to eliminate any fatty parts from the meat; cut it into pieces and put it in an oven dish with the vegetables, which you have cleaned and coarsely chopped. Add the prunes and the chocolate broken into pieces, season with salt, pepper and olive oil, and give everything a good stir. Cover the dish and cook in a preheated oven, at 160 °C, for at least 2 and a half hours. Stir from time to time and if you see that the meat is drying out too much, add a little hot water. When cooked, serve the stew with some toasted bread (it’s impossible to resist “mopping up” the sauce!) and, if you like, a drizzle of extra virgin olive oil with rosemary.