Mix flour, salt and pepper in a resealable plastic bag. One at a time, put chicken pieces in bag, seal and shake to coat. In a large skillet, heat oil over medium heat and saute chicken pieces until brown on all sides. Place chicken in a lightly greased 9x13 inch baking dish and bake covered in the preheated oven for 45 minutes.
To Make Sauce (while chicken bakes): In the same large skillet, saute onion and green bell pepper for about 5 minutes, until translucent. Add the pineapple, soy sauce and brown sugar. Mix together cornstarch and chicken stock and add to skillet. Stir all together and let simmer for 3 minutes until thick and clear. Pour sauce over chicken and bake 10 more minutes until tender.
