Preheat oven to 400 degrees F.
In 2 large zip-top bags, divide half the flour, garlic powder, onion powder, mustard powder, oregano, thyme, salt, and black pepper between each bag. Place 6 chicken breasts in each bag. Seal bags and shake to coat. Remove chicken from bag, shaking off excess coating.
Transfer chicken to baking sheet and spray with olive oil cooking spray. Bake 25 to 30 minutes, until chicken is golden brown and cooked through.
Serve 4 chicken breast halves with Parsley Olive Oil Sauce for this meal and refrigerate remaining chicken until ready to use.
In mini-food processor, place parsley leaves. Drizzle in olive oil and process to combine. Add more olive oil until desired sauce consistency is achieved. Season with salt and pepper, to taste. Spoon over chicken and serve.