1 Heat the oil in a large pot over medium heat. Add the onion and sauté for 5 minutes, or until translucent. If not using oil, just sauté with broth.
2 Reduce the heat to medium-low. Add the barley, garlic, and thyme and sauté for 3 minutes.
3 Stir in the mushrooms. Add the broth, tomato paste, vinegar, miso, bay leaf, and 1/4 teaspoon salt and stir to combine. Bring the soup to a boil. Reduce the heat to low, cover, and simmer for at least an hour, or until the barley is tender. Note that this only took about 25 - 30 minutes for me to get the texture I wanted. (If using sorghum, it will be soft but slightly chewy once cooked.)
4 Remove the bay leaf. Season to taste with more salt, if desired, and black pepper.
5 Store leftover soup in an airtight container in the refrigerator for up to 2 days.
