Barley and Mushrooms with Beans

INGREDIENTS

• 1 teaspoon olive oil
• 3 cups sliced fresh mushrooms
• 1 cup chopped onion
• 1/2 cup chopped celery
• 2 cloves garlic, minced
• 1/2 cup uncooked barley
• 3 cups vegetable broth
• 1 (15.5 ounce) can white beans, drained