Beef Mushroom Barley Soup

Name: Beef Mushroom Barley Soup
Ingredients: 2 tablespoons plus 1 teaspoon canola oil; One 1 1/4- to 1 1/2-pounds beef shin on the bone, trimmed of excess fat; Kosher salt and freshly ground black pepper to taste; 1 carrot, diced; 1/2 onion, diced; 1 rib celery, diced; 1/2 teaspoon dried thyme; 6 cups water; 1/3 cup pearl barley, rinsed; 1 cup chopped canned tomato; 1 tablespoon unsalted butter; 3/4 pound medium-sized button mushrooms, brushed, trimmed, and quartered; 3 tablespoons minced flat-leaf parsley