In a large skillet, saute onions in butter until tender. Stir in flour. Gradually stir in 1 cup water. Bring to a boil; cook and stir for 2 minutes or until thickened. Transfer to a 5-qt. slow cooker., Add the broth, potatoes, potato flakes, bacon, pepper, salt, basil, thyme and remaining water. Cover and cook on low for 6-8 hours or until potatoes are tender. Stir in cream; heat through. Garnish with cheese and green onions.