1Heat oven to 350°F. Spray 10-inch skillet and 2-quart casserole with cooking spray. Cook barley in skillet over medium heat about 8 minutes, stirring constantly, until light brown.
2Stir in remaining ingredients except green onions; heat to boiling. Spoon mixture into casserole.
3Cover; bake about 50 minutes or until vegetables are tender. Sprinkle with green onions.