3 cups of vegetable stock and the barley should be combined in a saucepan.

Over medium heat, bring to a boil, cover, and simmer for an hour, or until the liquid has been absorbed.

In the meantime, add the onion, carrots, celery, and mushrooms to a large pot and heat the olive oil.

The vegetables should be covered and cooked for about 5 minutes, or until they start to soften.

Stir in the remaining vegetable stock, cover, and boil for 30 minutes.

Five additional minutes of simmering are required after adding the barley.

Ladle into dishes after adding salt to taste.

Serve with fresh parsley that has been chopped.