Mushroom Barley Soup

Name: Mushroom Barley Soup
Ingredients: 1 ounce dried porcini mushrooms ((or other dried mushrooms of choice)); 1 cup hot water; 3 tablespoons olive oil; 1 cup chopped onion; 2 garlic cloves ((minced)); 2 teaspoons fresh minced thyme ((or 1 teaspoon dried)); Kosher salt and freshly ground black pepper ((to taste)); 10 cups sliced and roughly chopped fresh mushrooms ((any type)); 2 tablespoons all-purpose flour; 8 cups less-sodium chicken or vegetable broth ((or more as needed)); 2 bay leaves; ½ cup pearl barley; Sliced scallions and chopped fresh parsley ((to garnish; optional))