Chicken with balsamic vinegar

In my most recent chicken saute recipes (here, for example), I have suggested covering the pot for a while, before uncovering it to allow the sauce to reduce. This one has vinegar, albeit of a mild kind, and requires reduction right from the start - hence the uncovered pan throughout. The disadvantage was that the cloves of garlic did not soften thoroughly. Nevertheless, I squeezed them from their skins about 10 minutes before the end of cooking, and mashed them into the sauce.

4 chicken thighs
4 drumsticks
1dstsp sunflower oil
Salt
150ml balsamic vinegar
6 garlic cloves, unpeeled
Chicken stock
Sprig of rosemary

In a heavy casserole or saute pan large enough to contain the chicken pieces in a single layer, fry the thighs and drumsticks, salted, gently, until brown. You should not need more oil, because the chicken pieces will exude their own fat. Pour in the vinegar, throw in the garlic cloves and rosemary and simmer gently, uncovered, for an hour to an hour and a half. (I like my chicken well-cooked; and this method will not tenderise it as efficiently as would a covered pan.)

When the vinegar turns syrupy and threatens to catch, thin it with a little stock; and keep adding more liquid as necessary. When you are nearly ready to serve, fish out the garlic cloves, slip the garlic from the skins, and mash it into the sauce.