Green Bean Casserole with Mushrooms and Crispy Onions Recipe

Introduction

Green bean casserole is a comforting and classic side dish that’s perfect for family dinners and holiday gatherings. This version features fresh green beans and mushrooms in a creamy white sauce, topped with crunchy crispy onions for a delightful texture contrast.

Ingredients

• 50g butter
• 2 tbsp olive oil
• 250g chestnut or button mushrooms, sliced
• 500g green beans, trimmed
• 50g flour
• 500ml milk
• 100g crispy onions

Instructions

1. Step 1: Heat 1 tablespoon of butter and the olive oil in a large pan over medium heat. Add the sliced mushrooms and fry for 10-15 minutes until they turn golden brown.
2. Step 2: Stir in the trimmed green beans and cook for another 3-4 minutes until the beans turn bright green. Then scoop the vegetables out onto a plate and set aside.
3. Step 3: Preheat your oven to 200°C (180°C fan) or gas mark 6. Melt the remaining butter in the pan until it starts to foam.
4. Step 4: Remove the pan from the heat briefly and sprinkle over the flour. Stir the flour into the melted butter to form a golden brown paste (roux).
5. Step 5: Return the pan to the heat and gradually add the milk a splash at a time, stirring continuously to avoid lumps. Continue until all the milk is incorporated and you have a smooth, thick white sauce. Season the sauce well with salt and pepper.
6. Step 6: Stir the cooked green beans and mushrooms into the white sauce until evenly combined. Spoon the mixture into a medium ovenproof dish.
7. Step 7: Scatter the crispy onions evenly over the top, then bake in the preheated oven for 20-30 minutes. Bake until the casserole is bubbling and golden on top. Cover loosely with foil if the onions brown too quickly.

Tips & Variations

• For extra richness, add some grated cheese to the white sauce before baking.
• If you’re short on time, you can swap the homemade white sauce for a can of cream of mushroom soup.
• Use fresh green beans for the best texture, but frozen green beans will work in a pinch—just thaw and drain them well before cooking.

Storage

Store any leftover casserole in an airtight container in the refrigerator for up to 3 days. To reheat, cover the dish with foil and warm in a 160°C (140°C fan) oven until heated through, about 15-20 minutes. Avoid microwaving if possible to keep the crispy onion topping crunchy.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this casserole ahead of time?

Yes, you can assemble the casserole a few hours before baking. Keep it covered in the fridge and add the crispy onions just before baking to keep them crisp.

What can I use instead of crispy onions?

You can substitute crispy fried shallots, toasted breadcrumbs, or crushed fried onions for a similar crunchy topping.

Green Bean Casserole with Mushrooms and Crispy Onions Recipe

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★★★★★

4.7 from 54 reviews

• Author: Ben
• Total Time: 55 minutes
• Yield: 6 servings 1x
• Diet: Vegetarian

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Description

This classic Green Bean Casserole features tender green beans and sautéed mushrooms enveloped in a creamy homemade white sauce, topped with crispy onions for a delightful crunch. Perfectly baked to a golden brown, this comforting side dish is a staple for family meals and holiday dinners.

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Ingredients

Scale 1x2x3x

Vegetables

• 500g green beans, trimmed
• 250g chestnut or button mushrooms, sliced

White Sauce

• 50g butter, divided
• 2 tbsp olive oil
• 50g flour
• 500ml milk

Topping

• 100g crispy onions

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Instructions

1. Sauté Mushrooms: Heat 1 tbsp of butter and the olive oil in a large pan over medium heat. Add the sliced mushrooms and fry for 10-15 minutes until they turn golden brown, stirring occasionally to prevent sticking.
2. Cook Green Beans: Stir in the trimmed green beans with the mushrooms and cook for an additional 3-4 minutes until the beans turn a bright green color and are tender-crisp. Then scoop out the vegetable mixture onto a plate and set aside.
3. Make White Sauce: Preheat the oven to 200°C (180°C fan)/gas mark 6. In the same pan, melt the remaining butter until foaming. Remove the pan from heat briefly and sprinkle the flour over the melted butter, stirring swiftly to create a golden brown paste (roux). Return the pan to the heat and gradually add the milk a splash at a time, stirring continuously to avoid lumps and achieve a smooth, thick white sauce. Season the sauce well with salt and pepper to taste.
4. Combine and Bake: Stir the cooked green beans and mushrooms into the white sauce until fully incorporated. Transfer the mixture into a medium ovenproof dish and spread it evenly. Scatter crispy onions evenly over the top.
5. Bake: Place the dish in the preheated oven and bake for 20-30 minutes until the sauce is bubbling and the crispy onions are golden brown. If the onions start browning too quickly, cover the dish loosely with foil to prevent burning. Remove from oven and let it cool slightly before serving.

Notes

• For a richer flavor, add cheese to the white sauce before combining with the vegetables.
• For a quicker version, you can substitute the homemade white sauce with a can of cream of mushroom soup.
• Ensure green beans are fresh and trimmed well for best texture.
• Cover the casserole if topping browns too fast during baking to avoid burning the onions.

• Prep Time: 15 minutes
• Cook Time: 40 minutes
• Category: Side Dish
• Method: Baking
• Cuisine: American

Keywords: Green bean casserole, green beans, mushroom casserole, baked side dish, holiday side dish, crispy onions, comfort food