Heat 1 tbsp of the oil in a large casserole dish. Sear the beef on all sides over a medium high heat, allowing a dark crust to develop. Do this in 2–3 batches, adding more oil each time. Set aside.
Turn up the heat and pour in the wine along with the thyme. Bring to the boil, pushing the thyme around as you go. Reduce the wine by just over half, then pour off into a jug and discard the thyme. Wipe out the casserole dish.
Heat the remaining oil in the casserole and add the onion, carrot and celery. Cook until the onion and celery are translucent, then turn up the heat to caramelise slightly.
Drop the bouquet garni into the casserole along with the orange zest, garlic, oregano, anchovies and tomato purée. Stir to combine, then return the meat to the pan. Pour over the wine and stock, then season.
Bring to the boil, cover and reduce the heat. Leave over a very low heat for 2 hours, or until the meat is tender.
At this point you can serve the dish as a casserole. To turn it into a ragù, allow it to cool a little, then break up all the meat, removing any unforgiving pieces of connective tissue. Squeeze the garlic out of its skins and remove the bouquet garni.
Stir well over a low heat to reduce to a thick sauce. While the ragù reduces, heat 1 tbsp olive or rapeseed oil in a large frying pan, add the minestra nera with 100ml water and cover. Braise for 10 minutes, until the greens are just tender.
Serve with the butter beans.