Mushroom Barley Soup

Name: Mushroom Barley Soup
Ingredients: 2/3 cup pearl barley (use quick-cooking barley or soak barley in water overnight to cut cooking time); 64 oz. reduced-sodium chicken or vegetable broth (or use any variety); 2 Tbsp. extra virgin olive oil; 1 yellow onion (chopped); 2 cloves garlic (minced, about 1 tsp.); 16 oz. sliced cremini or white button mushrooms; 2 stalks celery (thinly sliced); 3 carrots (thinly sliced); 1 Tbsp. Worcestershire sauce; 2 Tbsp. sherry (or use 1 Tbsp. rice wine vinegar); 1/4 tsp. salt (or to taste); 1/8 tsp. black pepper (or to taste)