In a casserole, just large enough to hold the pork, heat the butter and oil until the foam begins to subside.
Add the pork and brown on all sides...using thongs to turn,regulating heat so butter does not burn.
Season the pork with salt and add the peppercorns,bay leaves and red wine vingar.
Scrape up any brown bits, lower heatand simmer,
overed until very tender, 1- 1/4 hours...more if preferred.
If the liquid should dry up add 2-4 tbs of water
When cooked, remove the pork to a platter to rest, disgard any fat and the bay leaves.
Add 1/2 cup water and bring to a boil, deglazing the pan.
Slice the pork and pour the sauce over...