Cut the ends off the carrots, celery and onions, peel the carrots and onions and wash the celery, then chop them for the mirepoix.
Rinse the oxtail pieces and put them in a large pan. Add the vegetables, salt and add 3 glasses water, then bring to the boil over high heat.
When the water starts to boil, cook for 5 minutes then add the peeled tomatoes, the concentrate, the rum and the spices (not the chocolate). If necessary add water to cover, lower the heat to minimum setting, put the lid on the pan and simmer for two hours, occasionally turning the pieces of meat.
Add the flakes of plain chocolate and turn the meat again, letting it simmer for about another hour and a quarter, checking the level of the liquid and if necessary adding vegetable stock.
The meat is cooked when it comes off the bone easily. Remove the oxtail pieces from the sauce and leave them to cool. Now take the meat off the bone and put back into the sauce. Before serving, heat up the sauce and meat together, stirring well. This dish can be served with sticks of hot polenta or with spatzle (small dumplings).
The paired recipes are suggestions given by the Personal Chef Alessandra Prizzon blog: Gustosamente Insieme