Bake chicken at 350°F for about 30 minutes until no pink. Cut into cubes, shake a few shakes of soy sauce over chicken, sprinkle with sugar and cornstarch and set aside.
While chicken is cooking, chop onion, pepper, and cabbage. Shred carrot. Put 2 Tbsp. of oil in pan and saute vegetables, once they are translucent add bean sprouts and sprinkle generously with soy sauce. Let sprouts cook down till soft, about 10 minutes at med heat, and then drain very well in colander. After well drained, add chicken back in and heat everything thru for about 10 minutes, drain again.
Take egg roll wrappers and separate, put heaping Tbsp. of mixture in center and follow directions for wrapping on package. Heat oil up and deep fry for a few minutes on each side. Watch carefully. Drain on paper towels.