Heat the olive oil in a large skillet until hot. Add the pork to the skillet. Cook for 2 minutes, stirring often.
Add all of the vegetables to the skillet. Sprinkle with lime juice, chili powder, and a sprinkle of salt and pepper. Cook for 3 to 4 minutes longer, stirring often, until the vegetables begin to soften and the pork cooks through.
Add the broth/cornstarch mixture to the skillet and cook just until the liquid comes to a boil and begins to thicken. Serve over polenta.