Peel onion, carrots and potatoes. Finely dice onion, cut carrots and potatoes into small cubes. Finely dice celery.
(If using, you can also add your freezer stash vegetables "bits" add green parts of the leek, fennel fronds)
Heat oil in a large saucepan over medium heat. Add onion and salt. Cook, stirring for 2 minutes. Add carrot and celery and cook for another minute, stirring.
Add water, pearl barley, chicken, bay leaves and peppercorns. Increase the heat and bring to the boil. Cover and simmer very gently on low heat for 30 minutes, stirring every now and again. Add some extra water to the soup and season with extra salt if you prefer a more runny consistency.
Remove chicken from the soup and shred, the meat, including the skin. Return to the soup.
(Remove any frozen whole vegetable "bits" if using, such as fennel fronds, etc. Discard or chop up finely and add back to the soup)
Serve with a tablespoon or two of fresh cream or milk stirred through the soup. Sprinkle with dill.