Spatchcock the chicken: Hold chicken on a cutting board with the backbone facing you and the neck down on the cutting board. Using your knife or shears, cut on either side of the backbone. Save the bone for chicken stock. Turn over the chicken and press down on the breastbone with the heel of your hand until you hear a crack and the chicken is all one thickness. You can also use a kitchen scissor to cut the wishbone.
Combine ginger, orange zest, coriander, salt, black pepper and sesame oil in a small bowl. Rub ginger-orange mixture all over chicken, place on roasting pan and roast for 45 minutes.
While chicken is roasting, combine hoisin sauce and orange juice.
After 40 minutes of roasting, remove chicken from oven and glaze chicken with hoisin orange mixture. Place chicken back in the oven and roast an additional 5-8 minutes. Remove from oven and serve warm with remaining hoisin-orange sauce.