Heat the oil in a large cooking pot. Sauté the onions. Add garlic and stir. Sauté till the onions turn light golden brown.
Add barley, leeks/mushrooms, grated carrot, celery, bay leaves, spices, salt, pepper and stir. Sauté a few minutes.
Add the chicken broth. Bring it all to a boil. Lower the heat and simmer for about an hour or more until the barley has cooked to a very soft texture.
Using a hand blender or a table top blender process half of the soup ingredients to a smooth consistency. Mix it back with the remaining soup.
Adjust the consistency of the soup with more broth if needed. Adjust the salt and seasoning. Add lemon juice as per taste.
Scoop out some soup into a bowl and mix with sour cream and return it back to the soup pot and stir it.
Stir one tablespoon of cilantro into the soup. Garnish the Persian Creamy Barely Soup with the remaining cilantro.
Notes
I prefer to process only half the soup to a creamy consistency and mix it with the rest. If you want to process more or less, you may do that as per your taste.
Persian spice mix (Advieh) recipe is on the blog. Ready made advieh is available at Persian or middle eastern grocery stores or online.
May use a middle eastern or Mediterranean mixed spice as a substitute.