Roast the whole chicken in an 180C oven for 1.5 hours, or according to its weight. Allow to cool, remove all the meat. Use the carcass to make the chicken stock. This can be done the day before.
Place the carcass in a saucepan large enough for the bones, veg and about 2.25 litres of water.
Add the water and bring to a very gentle simmer. Don’t boil! This is the secret of perfect clear stock. When white scum rises to the surface, skim it off with a spoon. Add the veg on top of the bones.
Place the pot half on, half off the heat. The gently simmering stock will rise and fall through the veg, which act as a filter, absorbing impurities and leaving the liquid clear. Simmer for 2 hours. When the taste stops improving it’s ready.
Remove from the heat and pour through a sieve into Tupperware. Cover and put in the fridge. Leave overnight and in the morning lift off any fat with a spoon and discard. The stock should now be jelly-like. It will keep in the fridge for 5 days or freeze for up to 3 months.
For the soup, gently heat the clear stock and add the veg for 5-10 minutes until tender. Add the chicken meat and herbs and serve.