Description
This French Green Bean Casserole is a sophisticated twist on the classic holiday side dish, featuring tender haricots verts, sautéed mushrooms, and a creamy, cheesy sauce topped with crispy fried onions. It offers a rich blend of flavors with Gruyère or Parmesan cheese making it perfect for festive dinners or comforting family meals.
Ingredients
Scale
Vegetables
- 1 ½ pounds French green beans (haricots verts), trimmed
- 1 small yellow onion, finely chopped
- 2 cloves garlic, minced
- 8 ounces cremini or white mushrooms, sliced
Dairy & Fats
- 2 tablespoons unsalted butter
- 1 cup whole milk
- ½ cup heavy cream
- 1 cup grated Gruyère or Parmesan cheese
Dry Ingredients & Seasonings
- 2 tablespoons all-purpose flour
- ½ teaspoon salt
- ¼ teaspoon black pepper
- â…› teaspoon ground nutmeg
- 1 cup crispy fried onions (plus extra for topping)
Instructions
- Preheat and blanch: Preheat your oven to 375°F (190°C). Bring a large pot of salted water to a boil. Add the green beans and blanch for 3 to 4 minutes until they are bright green and slightly tender. Drain and immediately transfer to a bowl of ice water to stop cooking. Drain again and set aside.
- Sauté vegetables: In a large skillet, melt the butter over medium heat. Add the chopped onion and cook for 3 to 4 minutes until soft. Stir in the garlic and mushrooms, cooking for another 5 to 6 minutes until the mushrooms release moisture and begin to brown.
- Make the sauce: Sprinkle in the flour and stir continuously for 1 minute to form a roux. Slowly pour in the milk and cream while whisking to prevent lumps. Cook until the sauce thickens, about 3 to 4 minutes. Add salt, pepper, nutmeg, and cheese, stirring until the cheese melts into a smooth sauce.
- Combine and bake: Fold the blanched green beans and half of the crispy fried onions into the sauce. Transfer the mixture to a greased 2-quart baking dish. Top with the remaining crispy onions and bake for 20 to 25 minutes until bubbly and golden on top.
Notes
- You can prepare this casserole a day ahead: assemble it, cover, and refrigerate. Bake just before serving for convenience.
- For extra depth of flavor, add a splash of white wine to the mushroom mixture during cooking.
- Gruyère cheese imparts a rich French flavor, but Parmesan is a great substitute if preferred.
