Combine barley and Taking Stock Foods Classic Chicken Bone Broth in a medium saucepan. Bring to a boil, lower to a simmer and cover pot. Simmer for 25-30 minutes, until tender and chewy. Cool to room temperature.
Meanwhile, heat the olive oil over medium heat. Add mushrooms, and cook until browned and fragrant. Add the rosemary and garlic and cook for a few minutes longer. Cool to room temperature.
When barley and mushrooms are cooled, stir together in a large bowl. Add mozzarella. Garnish with green onions. Serve at room temperature. If refrigerating, allow to return to room temperature for 45 minutes before serving.