Heat oven to 350. Lightly spray 2- 9" x 13" pans w/ cooking spray. In lg skillet, heat oil over med-high heat. Cook chicken, a few pieces at a time until browned on all sides. Remove chicken to pans, dividing evenly in pans.
Add flour to skillet and cook over medium for 30 seconds, or until golden, stirring constantly. Add celery, green peppers and onions. Cook until veggies are tender, about 5 mins, stirring often.
Stir in broth, salt and hot pepper sauce. Bring to a boil. Pour sauce evenly over chicken in both pans. Bake, uncovered about 1 hr, or until chicken is no longer pink inside, basting occasionally w/ gravy.