In a big pot on medium heat, soften the onions for about 3 minutes. Add garlic and cook for 2 minutes. Add carrots and celery and cook for another two minutes.
Add all the other ingredients and bring to a boil. Reduce to low heat, cover and let simmer for 1hour to 1h30, until the barley is cooked and the veggies are tender. Add water or broth if too thick.
Add salt & pepper to taste.
Notes
You can freeze this soup in single portions to make the pleasure last longer.