Heat oil in a large pot over high heat. Add pork roast, and brown on both sides, about 5-7 minutes per side.
Transfer the roast to a baking dish.
In the same skillet, add onions, peppers, and garlic. Saute until softened, and then add salt and spices.
Continue to saute, and add broth and canned tomatoes. Use a spatula to begin breaking up tomatoes, and allow to simmer about 10 minutes.
Add the tomato stew into the baking dish around the pork roast.
Bake on 250º F for 1 hour 45 minutes in the Sharp Superheated Steam Countertop Oven.
If baking in a traditional oven, cover the baking dish with foil or a lid, and bake on 250º F for 2 – 2 1/2 hours, until the pork shreds very easily.
Remove baking dish from oven, and stir in vinegar and chopped olives. Garnish with cilantro, if desired.