Cut the short ribs into individual ribs and coat in flour. Heat a heavy-based casserole with a film of oil and the knob of butter in it. Add the floured ribs and lightly brown on all sides. Reserve.
Add another knob of butter, followed by the vegetables and garlic, and lightly brown them.
Deglaze the pan with the vinegar and reduce by two-thirds. Then add the port and wine, and