Thinly slice pork tenderloin and season with salt. Add cornstarch to the meat, mix well and form sliced pork into 1½ inch balls.
Heat large skillet over medium heat and add olive oil. Place meatballs in the skillet and pan fry for 20 minutes or until brown. When done, take meatballs out of the skillet and set it aside.
Using the same skillet meatballs were cooked in, add olive oil and keep the heat on medium. Add bell peppers in the skillet first and stir fry for 3 minutes, then add white onions and stir fry for 2-3 minutes. Sprinkle salt over vegetables.
When vegetables become soft, add back pork meatballs and stir in sweet & sour sauce. Coat pork and vegetables with sauce and transfer to serving platter.