Clean chicken well and rub the whole chicken inside and out with the combined marinade.
Stuff the spring onion in the chicken cavity then seal with a small sharp skewer. Leave aside for at least 30 minutes.
In an old wok, heat the coarse salt over a medium low heat until the salt is warm to the touch.
Wrap the chicken with the greaseproof paper. Spread two ladlefuls of the warm salt onto the aluminium foil. Put the wrapped up chicken package on top of the salt. Cover with another 2 ladlefuls of warm salt. Wrap up the foil into a package.
Make a well in the centre of the remaining heated salt in the wok and place the package of chicken in it. Cover the wrapped package with salt and leave it to cook over medium heat for 20-25 minutes.
Remove the package and reheat the salt.
Keep stirring the salt until it is evenly heated. Return the package to the heated salt. Cover up again with salt and cook for another 20-25 minutes over medium low heat.