Description
A classic creamy green bean casserole featuring sautéed mushrooms and fresh green beans in a smooth white sauce, topped with crispy fried onions and baked to golden perfection. This comforting side dish combines rich flavors and textures perfect for holiday dinners or family meals.
Ingredients
Scale
Vegetables
- 1 lb 2 oz green beans, trimmed
- 2¾ cups sliced cremini or button mushrooms
Fats and Oils
- 4 tbsp butter
- 2 tbsp olive oil
Thickening and Liquid
- 6½ tbsp all-purpose flour
- 1¾ cups whole milk
Toppings
- 1–2 cups crispy onions
Instructions
- Sauté Mushrooms and Green Beans: Heat 1 tablespoon of butter and all the olive oil in a large pan over medium heat. Add the sliced mushrooms and fry them for 10 to 15 minutes until they turn golden brown. Stir in the trimmed green beans and continue cooking for another 3 to 4 minutes until the beans brighten in color. Once cooked, transfer the vegetables to a plate and set aside.
- Make the White Sauce: Preheat the oven to 400°F (gas mark 6). In the same pan, melt the remaining 3 tablespoons of butter over medium heat until it foams. Remove the pan briefly from the heat and sprinkle the all-purpose flour over the melted butter. Stir briskly to form a golden brown paste (roux). Return the pan to the heat and gradually add the whole milk, pouring it in a splash at a time while continuously stirring to achieve a smooth, thick white sauce. Season well with salt and pepper to taste.
- Combine and Assemble: Stir the sautéed mushrooms and green beans into the prepared white sauce, mixing thoroughly. Spoon the mixture into a medium-sized ovenproof dish, spreading it evenly.
- Add Crispy Onions and Bake: Scatter 1 to 2 cups of crispy fried onions evenly over the top of the casserole. Place the dish in the preheated oven and bake for 20 to 30 minutes until the sauce is bubbling and the onions have turned golden brown. If the onions brown too quickly, cover the casserole loosely with foil to prevent burning.
Notes
- For a richer flavor, use cremini mushrooms instead of button mushrooms.
- Trim and wash green beans thoroughly for the best texture and color.
- Adjust the amount of crispy onions according to your preference for crunchiness.
- To make ahead, prepare the casserole up to the baking stage, cover, and refrigerate. Bake just before serving, adding extra time if cold from the fridge.
- To make it gluten-free, substitute all-purpose flour with a gluten-free flour blend.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Category: Casserole
- Method: Baking
- Cuisine: American
Keywords: green bean casserole, mushroom casserole, holiday side dish, creamy casserole, crispy onion topping
