Start by prepping your veg: peel and roughly chop the onions and garlic, trim and roughly chop the celery and roughly chop the tomatoes.
Put the chicken, onions, garlic, celery and tomatoes into your largest saucepan. Add enough cold water to cover it all, pop the lid on, and bring to the boil over a high heat – about 30 minutes.
Once boiling, reduce to a simmer over a medium heat with the lid askew and cook for 1 hour, or until the chicken is cooked through.
Carefully lift the chicken out with tongs and put aside (use in the Leftover chicken with tomatoes & chorizo recipe). Pour the soup through a fine sieve, discarding what’s left behind. To further clarify it, strain through 4 layers of muslin. Have a taste to check the flavour balance, and season with sea salt and black pepper, if needed.
Skim off fat if serving straightaway. If you’re leaving it for another time, chill, then scoop off any fat that sets on the surface. Gently reheat the soup before serving. If you think it needs a bit of a colour boost, scoop out a cup of the broth and add 1 tablespoon of tomato purée to it. Mix until well combined then return to the broth and mix again.
Delicious served simply with a drizzle of basil oil, a few herb tips and a shaving of Parmesan, if you like.