4 tablespoons unsalted butter, divided
1/3 cup panko bread crumbs
1 large sweet onion, halved lengthwise, thinly sliced
2 teaspoons balsamic vinegar
2 tablespoons all-purpose flour
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
1/2 teaspoon freshly grated nutmeg
2 garlic cloves, finely chopped
3/4 cup 33% less sodium chicken broth*
1 cup half-and-half
1/4 cup grated Asiago cheese (1 oz)
1 (14.5oz) can French style or cut green beans, drained
1 (15oz) can Mrs. Grimes® Navy Beans or Great Northern Beans, drained, rinsed
*substitute vegetable broth to make this recipe vegetarian
Heat oven to 400°F. Spray shallow 2-quart casserole or 7×10-inch (2-quart) glass baking dish with cooking spray.
In 10-inch nonstick skillet, melt 1 tablespoon of the butter over medium heat. Stir in panko bread crumbs until coated. Pour into small bowl. Melt 1 tablespoon of the remaining butter in same skillet. Add onion. Cook over medium-high heat 10 minutes or until browned and tender, stirring frequently. Stir in balsamic vinegar. Spoon into medium bowl.
Melt remaining 2 tablespoons butter in same skillet. Stir in flour, salt, pepper, nutmeg and garlic. Cook over medium heat until bubbly and smooth; cook 1 minute, stirring constantly. Stir in broth. Bring to a boil; cook 1 minute, stirring constantly. Stir in half-and-half. Reduce heat; simmer uncovered 3 minutes or until slightly thickened, stirring frequently. Stir in cheese. Stir in green beans and white beans; mix slightly to coat.
Pour into casserole. Top with onions and buttered bread crumbs.
Bake 15 minutes or until bubbly around edges and top is golden brown. Let stand 5 minutes.