Season the rabbit legs. Melt the butter in a heavy-based casserole and colour the rabbit all over in it. Take out of the casserole and reserve.
Swill the casserole with the vinegar and boil to reduce by two-thirds. Add all the remaining ingredients and bring to the boil. When boiling, add the rabbit back to the casserole, cover and cook gently until the meat falls freely from the bone.<