FRENCH ONION GREEN BEAN CASSEROLE

French Onion Green Bean Casserole image

The iconic green bean casserole is reworked with the flavors of French onion soup -- caramelized onions and Gruyere cheese.

Provided by Chef John

Categories Side Dish Casseroles Green Bean Casserole Recipes

Time 1h30m

Yield 10

Number Of Ingredients 15

Ingredients

2 tablespoons butter
2 large yellow onions, thinly sliced lengthwise
salt and ground black pepper to taste
1 tablespoon sherry vinegar
2 tablespoons butter
2 ½ tablespoons all-purpose flour
2 ½ cups milk
1 pinch ground nutmeg
1 pinch cayenne pepper to taste
¼ teaspoon ground thyme
2 tablespoons melted butter
⅔ cup panko bread crumbs
2 pounds fresh green beans, trimmed
4 ounces shredded Gruyere cheese, divided
⅓ cup grated Parmesan cheese

Steps:

Preheat oven to 375 degrees F (190 degrees C). Grease a 9x13 inch casserole dish.
Heat 2 tablespoons of butter in a large skillet over medium heat. Stir the onions into the pan; cook and stir until very soft and golden brown, about 15 minutes. Stir in sherry vinegar. Transfer to a small bowl, and reserve.
In the same skillet, melt 2 more tablespoons butter. Whisk in 2 tablespoons flour. Stirring constantly, cook over medium heat until the flour smells like baked pie crust, about 3 minutes. Slowly whisk in milk, about 1/2 cup at a time, then whisk in nutmeg, cayenne pepper, and thyme. Bring to simmer, and cook until thickened, whisking constantly, 3 more minutes. Transfer to a bowl and reserve.
Melt remaining 2 tablespoons butter in clean skillet; stir in panko until all crumbs are coated; reserve.
Bring a large saucepan of salted water to a boil over medium heat, and boil beans until bright green and crisp but not raw tasting, 3 to 4 minutes. Drain very well.
Spoon half of the caramelized onions into the prepared casserole dish; top with green beans. Season with salt and black pepper. Spread reserved white sauce over the green beans; sprinkle with half of the Gruyere cheese. Top with the rest of the onions, and use the back of a spoon to push onions down into sauce and cheese. Top with the buttered panko crumbs, the remaining Gruyere, and Parmesan cheese.
Bake in the preheated oven until hot throughout and lightly browned, about 30 minutes. Let sit 10 minutes before serving.

Nutrition Facts : Calories 216.5 calories, Carbohydrate 18.9 g, Cholesterol 38 mg, Fat 13 g, Fiber 3.7 g, Protein 9.4 g, SaturatedFat 7.9 g, Sodium 195 mg, Sugar 5.5 g