The night before place chicken in a ziplock back.
Add olive oil, rosemary and lemon juice and the sliced lemon.
Close bag and shake the chicken till all of it is covered in the olive oil.
Refrigerate for 4 hours or overnight.
Preheat oven to 400 degrees.
Spray 9x13 pan with non stick cooking spray.
Place chicken in pan and cover with aluminum foil.
Cook for 40 minutes or until chicken is done.
Take off foil and cook for 5 more minutes.
Serve and ENJOY!