Heat oven to 350°F. In 4-quart saucepan, melt butter over medium-high heat. Add onions; cook 2 to 3 minutes, stirring frequently, until tender. Stir in flour, bouillon, thyme and pepper until well blended. Gradually stir in broth and milk, cooking and stirring until bubbly and slightly thickened. Stir in potatoes, carrots and green beans. Heat to boiling, stirring occasionally. Cook 8 to 10 minutes, stirring frequently, until vegetables are crisp-tender. Stir chicken into vegetable mixture; return to boiling.
Meanwhile, separate dough into 8 biscuits. Grease casserole dish with cooking spray. Pour chicken mixture into oven proof casserole dish. Place biscuits on top of liquid closely and carefully. Bake 20 to 25 minutes or until vegetables are tender and biscuits are golden brown. Let stand 5 minutes before serving. Enjoy!!!