This recipe is from a dear friend, and it has become one of my weekly comfort meals in the winter. It is absolutely delicious, and you can tweak it all you like. It is very fast to put together and almost completely fat-free. I love this soup.
Meanwhile, heat the olive oil and butter in a saute pan over medium heat.
Add the onion, celery, garlic, parsley, red pepper flakes, and the remaining herbs and saute until the vegetables are softened but not browned (about 5-6 minutes.) When the barley has cooked for 30 minutes, add this mixture to it along with the carrots and potatoes.
Cook everything together at a simmer for another 30 minutes.
Serve with a generous sprinkle of parmesan on top.