Description
This classic Green Bean Casserole recipe features tender green beans tossed in a creamy mushroom sauce, topped with crispy fried onions and baked to perfection. A timeless holiday favorite that combines savory mushrooms, buttery onions, and a rich béchamel-style sauce for a comforting side dish that serves six.
Ingredients
Vegetables
- 3 lb. green beans, trimmed
- 2 yellow onions, thinly sliced
- 1 lb. cremini mushrooms, sliced
- 4 cloves garlic, finely chopped
Dairy & Butter
- 12 tbsp. (1 1/2 sticks) unsalted butter, divided
- 6 c. whole milk
Dry Goods & Condiments
- Kosher salt
- Freshly ground black pepper
- 1/2 c. (60 g.) all-purpose flour
- 1 1/2 c. French's fried onions
Instructions
- Blanch Green Beans: Preheat your oven to 350°F. Bring a large pot of water generously salted with kosher salt to a boil. Add the trimmed green beans and cook for 2 to 3 minutes until they turn bright green. Stir occasionally for even cooking. Remove the beans using a slotted spoon or tongs and immediately transfer them to an ice bath to halt the cooking process. Drain well and place in a large mixing bowl.
- Sauté Onions and Mushrooms: In a large pot or saucepan, melt 4 tablespoons of butter over medium heat. Add the thinly sliced onions and a large pinch of kosher salt. Cook, stirring occasionally, until the onions soften, about 7 minutes. Add the sliced cremini mushrooms and continue cooking while stirring frequently until the mushrooms have browned and reduced in size, about 7 minutes more. Stir in the finely chopped garlic and cook for an additional minute until fragrant. Season the mixture with salt and freshly ground black pepper to taste. Transfer this mixture to the bowl with the green beans.
- Make the Cream Sauce: Using the same pot, melt the remaining 8 tablespoons of butter over medium heat. Sprinkle in the all-purpose flour and cook while whisking frequently, allowing the flour to turn golden and develop a toasty aroma, about 3 minutes. Gradually whisk in the whole milk to prevent lumps, then season with salt and black pepper. Bring the mixture to a gentle simmer and cook, stirring occasionally, until the sauce thickens into a creamy consistency, approximately 4 minutes. Pour this sauce over the green bean and mushroom mixture and stir well to combine. Transfer everything to a 13 x 9-inch baking dish, spreading evenly.
- Bake the Casserole: Place the baking dish in the preheated oven and bake for about 30 minutes, or until the casserole is heated through and bubbling around the edges.
- Add Fried Onions and Finish Baking: Remove the casserole from the oven and sprinkle the French's fried onions evenly over the top. Return the dish to the oven and bake for an additional 5 minutes to warm the onions and add a crispy topping.
Notes
- Blanching the green beans helps retain their vibrant color and crisp texture before baking.
- Using whole milk in the sauce provides a rich, creamy texture; for a lighter version, you could substitute with 2% milk but the consistency will be less thick.
- Cook the flour and butter mixture long enough to remove the raw flour taste but be careful not to burn it.
- French's fried onions add a classic crunchy topping, but you can substitute with homemade crispy onions if preferred.
- Ensure the casserole is bubbling hot before adding fried onions to maintain optimal texture contrast.