Cut up the pork into thick 2 inch slabs. Put them into a pot with everything except the oil. Strong simmer(almost full boil) about an hour and a half. Remove the pork. Strain the sauce and return it to the pot. In a heavy frying pan or cast iron skillet, sear the pork on both sides in the oil to brown really well. Put it back into the pot with the sauce and simmer lightly another hour or so to thicken and further tenderize. Serve the pork over rice with the sauce.