Stir orange juice, zest, soy sauce, vinegar, honey, garlic and ginger in a labeled gallon freezer bag. Add raw chicken breasts, squeeze out excess air and seal.
Freeze before cooking: lay the bag flat on a tray and freeze promptly for up to 2 months. Keep cornstarch, rice and broccoli separate for cooking day.
Thaw the sealed bag on a rimmed tray in the refrigerator for 24 to 36 hours. Empty into a 4-quart slow cooker and discard the raw-chicken bag.
Cover and cook on high for 2 1/2 to 3 hours until chicken reaches 165°F. Lift chicken to a plate, stir cornstarch mixed with 2 tablespoons cold water into the sauce and cook covered on high for 10 to 15 minutes until lightly thickened.
During the final 30 minutes, bring rice and 1 3/4 cups water to a boil, cover and simmer on low for 15 minutes, then rest covered for 10 minutes. Steam broccoli for 5 to 7 minutes until tender.
Cut chicken into bite-size pieces and return to the hot orange sauce. Divide rice, broccoli and chicken among 4 bowls.
Refrigerate cooked leftovers within 2 hours and reheat covered in the microwave, stirring midway, until the chicken and rice reach 165°F.