Barley with Mushrooms and Green Onions

1 cup barley
1 14 1/2 ounce can roasted garlic chicken broth, about 2 cups
3 green onions, thinly sliced, about 1/2 cup
4 to 6 ounces fresh or canned mushrooms, sliced
salt and pepper to taste

Combine all ingredients in crockpot. Cover and cook on low for 4 to 5 hours.