Rinse chicken under cold water; pat dry inside and out with absorbent paper.

Combine the sesame seeds, ginger, hoisin sauce, honey, chinese five spice and garlic in a large plastic bag. Place the chicken in the bag and massage the marinade all over the chicken. Close the bag tightly around the chicken and refrigerate for at least 2 hours or overnight to marinate. Preheat oven to 180°C (160°C fan-forced).

Place eggplant in a flameproof baking dish; drizzle with the oil and toss to coat eggplant. Move the eggplant to the sides and place the chicken in the centre, breast-side down. Reserve any remaining marinade for basting.

Roast for 45 minutes. Turn the chicken, breast-side up, and eggplant. Baste the chicken with the reserved marinade and pan juices. Roast for a further 45 minutes, basting once during cooking. If over-browning, cover dish with greased foil.

Transfer the chicken and eggplant to separate dishes. Cover chicken with foil and rest in a warm place for 10 minutes.

Pour the pan juices from the dish into a heatproof jug; discard the fat from the surface of the pan juices. Return the pan juices to the baking dish with the vinegar and sugar; stir until the sugar dissolves. Bring to the boil, add eggplant and cook, stirring, for 1-2 minutes or until the eggplant is well coated.

Serve chicken with eggplant, sprinkled with green onions.