Remove all but 1 tablespoon oil from the skillet then saute garlic for 30 seconds. Add broccoli and saute 3 to 4 minutes. Meanwhile, whisk together chicken stock, hoisin, soy sauce, honey, orange zest and juice. Pour into the pan with broccoli and bring to a boil. Whisk together the cornstarch and water and pour into the sauce mixture. Simmer until thickened and glossy. Add chicken and cook an additional minute. Serve over rice.