Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Season the pork with ¼ teaspoon each salt and black pepper. Working in 2 batches, cook the pork until browned and cooked through, 2 to 3 minutes per side; transfer to a plate.
Heat the remaining tablespoon of oil in a second large skillet over medium-high heat. Add the bell peppers, shallots, ½ teaspoon salt, and ¼ teaspoon black pepper. Cook, tossing occasionally, until softened, 5 to 7 minutes.
Add the beans, olives, parsley, and vinegar to the skillet and toss to combine. Serve the pork topped with the vegetable mixture.