1In medium bowl, toss pork with egg. In 1-gallon resealable food-storage plastic bag, place Bisquick mix, salt and pepper; seal bag and shake to mix. Drain excess egg from pork. Place pork cubes in plastic bag; seal bag and shake to coat.
2In 12-inch nonstick skillet, heat oil over medium heat. Place pork in single layer in skillet. Cook 6 to 8 minutes, turning occasionally, until brown and crispy on outside and no longer pink in center. Drain on paper towels. Cover to keep warm.
3Reserve 1 tablespoon oil in skillet; discard any remaining oil. Add bell pepper mix and pineapple; cook over medium-high heat 2 to 3 minutes, stirring frequently, until vegetables are crisp-tender. Stir in sweet-and-sour sauce and pork; heat to boiling.