Description
A classic and comforting Green Bean Casserole featuring sautéed mushrooms and fresh green beans in a creamy homemade white sauce, topped with crispy fried onions and baked until golden and bubbling. This dish is perfect as a flavorful side for holiday meals or family dinners.
Ingredients
Scale
Vegetables
- 1 lb 2 oz green beans, trimmed
- 2¾ cups sliced cremini or button mushrooms
Fats & Oil
- 4 tbsp butter
- 2 tbsp olive oil
Dairy
- 1¾ cups whole milk
Other
- 6½ tbsp all-purpose flour
- 1–2 cups crispy onions
Instructions
- Sauté Mushrooms: Heat 1 tbsp butter and 2 tbsp olive oil in a large pan over medium heat. Add the sliced mushrooms and fry for 10-15 minutes until golden brown, stirring occasionally to ensure even cooking.
- Cook Green Beans: Stir in the trimmed green beans with the mushrooms and continue cooking for another 3-4 minutes until the beans turn bright green and are slightly tender. Then, scoop out the vegetables onto a plate and set aside.
- Make White Sauce: Preheat the oven to 400°F (200°C) or Gas Mark 6. In the same pan, melt the remaining 3 tbsp butter until foaming. Remove from heat momentarily and sprinkle the all-purpose flour over the melted butter, stirring continuously to form a golden brown paste (roux).
- Add Milk Gradually: Return the pan to the heat and slowly add the whole milk a splash at a time, continuously stirring to avoid lumps. Cook until you achieve a smooth, thick white sauce. Season the sauce well with salt and pepper to taste.
- Combine Vegetables and Sauce: Stir the sautéed mushrooms and green beans into the prepared white sauce, ensuring even coating. Transfer the mixture into a medium-sized ovenproof dish.
- Add Crispy Onions and Bake: Scatter 1 to 2 cups of crispy onions evenly over the top of the casserole. Place the dish in the preheated oven and bake for 20-30 minutes until the casserole is bubbling and the topping turns golden brown. Cover loosely with foil if the onions brown too quickly to prevent burning.
Notes
- If crispy onions are not available, you can make your own by thinly slicing onions and frying them until golden and crisp.
- This casserole can be prepared ahead of time, assembled, and refrigerated before baking.
- For a richer flavor, use cremini mushrooms instead of button mushrooms.
- Adjust seasoning of the white sauce to taste, adding garlic powder or nutmeg for additional flavor if desired.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
Keywords: green bean casserole, classic side dish, mushroom casserole, holiday side, crispy onion topping
