Preheat oven to 400° and spray a casserole baking dish with non-stick cooking spray.
Heat olive oil in a small skillet or sauce pan over medium heat. Add chopped onion, garlic, and balsamic vinegar. Sauté for 5-10 minutes or until onions are soft. Remove from heat.
In a large mixing bowl, whisk together Campbell's® Condensed Cream of Mushroom Soup, chicken or vegetable broth, and salt and pepper. Stir in onion and garlic mixture, drained Butter Kernel® Cut Green Beans, and drained and rinsed S&W® White Beans. Pour into prepared casserole dish. Top with French's® Crispy Fried Onions. Bake for 25-30 minutes, until bubbly and browned on top.