Bring a pan of salted water to the boil— It should be salty, like sea water.
Add the chicken to the salted water, breast side down, and simmer for 10 minutes.
Remove the chicken from the water, being careful not to rip the skin, and place in a roasting tray, breast up.
Allow the skin to steam dry and rub with a glug of oil, being careful not to burn your hands. Season with salt and pepper.
Add a few millilitres of the poaching liquid, stock or water into the bottom of the tray. With the legs facing the back of the oven, roast for 50 minutes, until the skin is blistering gold, and the juices run clear.
Allow to rest for at least 20 minutes, before carving.