Start to finish: 3 hours, 20 minutes (Active time: 45 minutes)
2 slices hearty white sandwich bread, torn into pieces
2 tablespoons unsalted butter, melted
1/4 teaspoon salt
2 cups canned fried onions
3 tablespoons unsalted butter
10 ounces white mushrooms, trimmed and sliced thin
1 teaspoon salt
1/2 teaspoon pepper
6 garlic cloves, minced
1/2 teaspoon dried thyme
1/4 cup all-purpose flour
1 1/2 cups chicken broth
1 1/2 cups heavy cream
1/2 cup dry white wine
2 pounds green beans, trimmed and cut into 1-inch pieces
1/4 cup cornstarch
For the topping: Pulse bread, melted butter, and salt in food processor to coarse crumbs, about 6 pulses. Combine bread crumbs and fried onions in bowl. Set aside.
For the casserole: Adjust oven rack to middle position and heat oven to 400 F. Melt butter in 12-inch skillet over medium heat. Add mushrooms, salt, and pepper and cook until mushrooms release their liquid, about 5 minutes. Increase heat to medium-high and cook until liquid has evaporated, about 5 minutes. Add garlic and thyme and cook until fragrant, about 30 seconds. Stir in flour and cook until golden, about 1 minute. Slowly whisk in broth, cream, and wine and bring to boil. Reduce heat to medium and simmer, stirring occasionally, until sauce is thickened, about 10 minutes.
Toss green beans with cornstarch in large bowl and transfer to 13 by 9-inch baking dish. Pour warm mushroom mixture evenly over green beans. Let cool completely.
Cover with aluminum foil and bake until sauce is bubbling and green beans are tender, 40 to 50 minutes, stirring green beans halfway through baking. Remove foil and spread topping over green beans. Bake until golden brown, about 8 minutes. Serve.
Nutrition information per serving: 278 calories; 186 calories from fat; 21 g fat (11 g saturated; 1 g trans fats); 54 mg cholesterol; 354 mg sodium; 18 g carbohydrate; 2 g fiber; 4 g sugar; 4 g protein.
For more recipes, cooking tips and ingredient and product reviews, visit https://www.americastestkitchen.com. Find more recipes like Green Bean Casserole in “Complete Make-Ahead .”
America’s Test Kitchen provided this article to The Associated Press.