Green bean casserole is a timeless comfort dish that brings warmth and nostalgia to any table. This creamy, savory bake combines tender green beans with a luscious sauce and a golden crisp onion topping that delivers delightful texture and flavor in every bite.
Whether served during holiday gatherings or as a satisfying family dinner, this casserole is sure to become a beloved staple. The rich sauce enveloping fresh green beans and mushrooms pairs perfectly with the crunchy onion topping, making it irresistible.
- Classic comfort food with creamy, savory sauce and crisp onion topping.
- Uses fresh or frozen green beans for convenience and versatility.
- Optional mushrooms and cheeses add depth and richness.
- Easy to prepare, make-ahead friendly, and perfect for holidays or everyday meals.
Ingredients
- Fresh green beans (900 g / 2 lb): Trimmed and cut into bite-size pieces for tender, crisp texture in the casserole.
- Mushrooms (300 g / 10 oz): Thinly sliced optional addition adding earthiness and savoriness to the dish.
- Medium onion (1): Finely chopped to infuse sweetness and flavor into the creamy sauce.
- Unsalted butter (3 tablespoons): Used to create a rich base for the roux and sauce.
- All-purpose flour (3 tablespoons): Thickens the sauce for a smooth, velvety consistency.
- Milk (2 cups): Whole or 2% milk to build the creamy texture of the sauce.
- Heavy cream (1 cup, optional): Adds extra richness and silkiness to the sauce.
- Salt and freshly ground black pepper: Seasoning to perfectly balance and enhance flavors.
- Garlic powder (1/2 teaspoon): Provides subtle aromatic depth matching the savory profile.
- Onion powder (1/2 teaspoon): Enhances onion flavor and adds complexity.
- Crispy fried onions (1 1/2 to 2 cups): Store-bought or homemade topping adds satisfying crunch and golden color.
- Grated Parmesan or cheddar (optional sprinkle): Offers a cheesy finish for extra indulgence.
Instructions
- Preheat the oven
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Set your oven to 175 °C (approximately 350 °F) to prepare for baking the casserole. This moderate temperature ensures the sauce thickens and the topping crisps beautifully without burning.
- Prepare the green beans
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If using fresh beans, blanch them in a pot of salted boiling water for 5–7 minutes until they turn bright green and are just tender. This step preserves their vibrant color and prevents mushiness. Drain well and set aside. Skip this if using thawed frozen beans.
- Cook the onions and mushrooms
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Melt butter in a large skillet over medium heat, then add finely chopped onions. Cook for 3–4 minutes until soft and translucent, developing their natural sweetness. If using, add sliced mushrooms and sauté briefly to deepen their flavor and improve texture before adding the roux ingredients.
- Make the creamy roux sauce
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Sprinkle flour evenly over the softened onion (and mushroom) mixture, stirring constantly for about a minute to cook out the raw taste. Slowly whisk in milk and optional heavy cream, stirring continuously to prevent lumps. Cook for 5–7 minutes until the sauce thickens and coats the back of a spoon, creating a luscious base for the casserole.
- Season the sauce
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Add salt, freshly ground black pepper, garlic powder, and onion powder to the sauce. Adjust seasoning to taste, ensuring a balanced, savory flavor that complements the vegetables perfectly.
- Combine green beans and sauce
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Gently stir the blanched green beans and sliced mushrooms into the creamy sauce, coating each piece thoroughly. This mixture forms the savory heart of the casserole.
- Assemble the casserole
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Transfer the green bean and sauce mixture into a baking dish spread evenly. Sprinkle the crispy fried onions uniformly over the top for a crunchy texture. Optionally, add a light sprinkle of grated Parmesan or cheddar cheese for a melty, flavorful crust beneath the onions.
- Bake to perfection
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Place the casserole in the preheated oven and bake for 20–25 minutes. The sauce will bubble gently, and the topping will turn golden brown and crisp, signaling it’s ready to serve.
- Serve warm
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Allow the casserole to cool for a few minutes after baking. Serving it warm lets the flavors meld, while the creamy texture and crunchy topping provide irresistible contrast in every bite.
- Blanching fresh green beans locks in their color and texture so they don’t become mushy when baked.
- Sautéing mushrooms enhances depth and prevents excess moisture in the casserole.
- For a crisp topping, add fried onions just before baking or during the final 5 minutes.
- Make-ahead tip: Assemble casserole without topping, refrigerate overnight, then add onions before baking.
- Mixing crushed crackers or panko with fried onions adds extra crunch and flavor.
Storage Tips
Store leftover green bean casserole in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven to refresh the sauce and crisp the topping. You can also freeze the unbaked casserole without the onion topping for up to 2 months.
Serving Suggestions
This casserole pairs beautifully with roasted meats like turkey or chicken, creamy mashed potatoes, or a fresh green salad for a balanced meal. It also works well as a hearty vegetarian main with crusty bread on the side.
- Use fresh green beans and blanch prior to baking for the best texture and color.
- Whisk sauce continuously when adding liquids for a smooth, lump-free texture.
- Optional cream in the sauce adds richness but can be omitted for lighter casseroles.
- Customize toppings with different cheeses or mixed crunchy crumbs to suit your taste.
- Rest casserole briefly after baking to allow flavors to meld and set for easier serving.
FAQs
- Can I use frozen green beans?
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Yes, thawed frozen green beans work well and save prep time. Just skip the blanching step and add directly to the sauce.
- How can I make this casserole gluten-free?
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Substitute all-purpose flour with a gluten-free flour blend or cornstarch slurry to thicken the sauce safely.
- Can I make the crispy onion topping at home?
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Absolutely! Thinly slice onions, coat in flour, and fry until golden brown for fresh crunchy topping.
- Is it possible to prepare this casserole in advance?
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Yes, assemble the casserole without crispy onions, refrigerate up to 24 hours, then add onions and bake when ready.
- What can I serve with green bean casserole?
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It pairs wonderfully with roasted meats like turkey, mashed potatoes, or simple salads for a complete meal.
- How do I get a crispy topping without burning?
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Add fried onions in the last 5 minutes of baking or monitor closely to prevent over-browning.
Green Bean Casserole Classic
Equipment
- 1 large pot for blanching green beans
- 1 large skillet to make sauce
- 1 baking dish for casserole
Ingredients
- 2 pounds fresh green beans trimmed and cut into bite-sized pieces (or use thawed frozen)
- 10 ounces sliced mushrooms optional
- 1 medium onion finely chopped
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 2 cups milk whole or 2%
- 1 cup heavy cream optional
- Salt and freshly ground black pepper to taste
- ½ teaspoon garlic powder
- ½ teaspoon onion powder
- 1½ to 2 cups crispy fried onions store-bought or homemade
- Optional: sprinkle grated Parmesan or cheddar cheese
Instructions
- Preheat oven to 350°F (175°C).
- If using fresh green beans, bring a large pot of salted water to a boil. Blanch green beans for 5 to 7 minutes until bright green and just tender, then drain and set aside.
- In a large skillet over medium heat, melt butter and cook chopped onion until softened, about 3 to 4 minutes.
- Sprinkle flour over onions and stir constantly for 1 minute to form a roux.
- Gradually whisk in milk and cream (if using), stirring to prevent lumps.
- Cook sauce, whisking frequently, until thickened and coats the back of a spoon, approximately 5 to 7 minutes.
- Season sauce with salt, black pepper, garlic powder, and onion powder.
- Add cooked green beans and sliced mushrooms to the sauce, stirring gently to combine.
- Transfer the mixture to a baking dish and evenly sprinkle crispy fried onions over the top.
- Optionally, sprinkle grated Parmesan or cheddar cheese before adding fried onions.
- Bake in the preheated oven for 20 to 25 minutes until the sauce bubbles and onions turn golden brown.
- Allow casserole to cool for a few minutes before serving warm.
Notes
- Blanching fresh green beans preserves color and tenderness without mushiness.
- Sauté mushrooms briefly for deeper flavor and better texture.
- Assemble casserole up to one day ahead without topping; add onions before baking.
- Enhance topping crunch by mixing crushed crackers or panko with fried onions.
- Pairs well with roasted meats, mashed potatoes, or fresh green salad.
