When ready to cook, arrange oven shelf to the middle of the oven, and preheat to 470°F | 245°C.
Remove the chicken from the refrigerator and let it sit on a bench top for 20 minutes, or just enough time to take the chill out of the chicken. (I find 20 minutes plenty of time. Don't leave it any longer than half an hour at room temperature.)
Heat 2 tablespoons of oil in an oven proof pan or well seasoned skillet over medium heat. When pan is hot, place the chicken, breast-side down into the pan, and sear for a good 5-6 minutes, until the skin becomes golden browned. Flip and sear on the other side for a further 5 minutes.
Add 2 more tablespoons of vegetable oil to the remaining marinade, and pour half of it over the chicken. Use a basting brush to coat evenly.
Place the chicken in the preheated oven, and cook for 20 minutes. Reduce heat down to 400°F (200°C) and roast for a further 35-40 minutes, or until cooked right through to the centre and juices run clear.
(If serving with the corn: completely wrap each cob in foil large enough to cover them, and add the corn foil packets to the same pan as the chicken, half way through cooking time (after 30 minutes). If your pan is too small, arrange them on another pan. They only need 30-35 minutes of cooking time.) Once corn is done, dollop with 1/2 teaspoon of butter per cob (optional).
Once the chicken is done, baste with the pan drippings and serve with any remaining UNTOUCHED marinade to use as a dipping sauce.
Serve with the corn!