Heat 2 tablespoons oil in a large, heavy Dutch oven or similar pan, add 1 cup chopped onions and cover and cook about 5 minutes over medium heat, stirring often, until the onions are softened but not browned. Reduce the heat, add the pork, with all the marinade, and the tomatoes, add an additional splash of wine, if using, cover and simmer 11/2 to 2 hours, until the pork is tender.
Remove the pork and keep warm. Spoon off fat, increase the heat and boil the sauce until it thickens. Adjust the seasonings. Pour over the pork and stir to coat. Serve with rice or warmed flour or rice tortillas.
Nutrition information per serving:
Calories410Fat...........................24 gSodium460 mg
Carbohydrates11 gSaturated fat7 gCalcium..............37 mg
Protein36 gCholesterol100 mgDietary fiber4 g