In a large bowl, combine cornstarch, salt, pepper, and egg until smooth. Add pork; toss to coat. In a skillet or wok, stir fry the pork in oil until no longer pink. Remove and set aside; keep warm.
Stir fry the carrots, onion, and garlic in oil for 3 minutes. Add green pepper and water; stir fry for 2 minutes. Drain pinapple, reserving 1/4 cup juice. Add pineapple and pork to the pan.
Combine cornstarch and brown sugar. Stir in chicken broth, vinegar, and soy sauce until smooth. Add ginger and reserved pineapple juice; add to pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Serve over rice