Best-Ever Green Bean Casserole Recipe
Introduction
This Best-Ever Green Bean Casserole elevates the classic side dish with fresh green beans, sautéed mushrooms, and a rich homemade béchamel sauce. Topped with crispy fried onions, it’s a comforting, crowd-pleasing recipe perfect for holiday dinners or any special meal.
Ingredients
- 2 lb. fresh green beans
- Kosher salt
- 2 Tbsp. extra-virgin olive oil, divided
- 1 lb. crimini mushrooms, sliced, divided
- 6 Tbsp. unsalted butter, divided
- 4 large sprigs thyme, divided
- 2 Tbsp. all-purpose flour
- 1¼ cups whole milk
- 1 cup heavy cream
- 4 garlic cloves, finely grated
- ½ cup grated Parmesan
- Freshly ground black pepper
- ¾ cup French’s fried onions
Instructions
- Step 1: Preheat your oven to 375°F and place a rack in the middle. Bring a large pot of salted water to a boil. Working in batches, cook the green beans until bright green and halfway tender, about 3 minutes per batch. Drain, let cool, and trim the stem ends.
- Step 2: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add half the mushrooms without stirring and cook until golden brown underneath, about 2 minutes. Toss and cook until browned on both sides, about 3 minutes more. Add 2 tablespoons butter and 2 thyme sprigs, tossing occasionally until butter browns and mushrooms are very tender, about 4 minutes. Season with salt and transfer to a plate. Repeat this process with the remaining mushrooms, butter, olive oil, salt, and thyme.
- Step 3: In a large saucepan over medium-low heat, melt the remaining 2 tablespoons of butter. Whisk in the flour and cook, stirring occasionally, until golden brown and nutty-smelling, about 4 minutes. Gradually whisk in the milk and cream, then increase heat to bring to a simmer, whisking often until thickened and bubbling, about 5 minutes. Remove from heat and stir in the grated garlic, Parmesan, salt, and pepper.
- Step 4: In a 2-quart baking dish, arrange the green beans and mushrooms. Pour the béchamel sauce evenly over the mixture. Cover tightly with foil and bake until bubbling, 25 to 30 minutes. Uncover and bake until lightly browned on top and edges, 15 to 20 minutes more. Sprinkle fried onions on top and bake just until they darken slightly and are fragrant, about 3 minutes. Let sit for 10 minutes to set before serving.
Tips & Variations
- Use fresh green beans for the best texture and flavor; frozen beans often turn mushy in casseroles.
- For a deeper mushroom flavor, add a splash of soy sauce or Worcestershire sauce when sautéing the mushrooms.
- To make this dish ahead, prepare up to step 4, then refrigerate covered. Add onions and bake just before serving.
Storage
Store leftovers covered in the refrigerator for up to 3 days. Reheat gently in a 350°F oven until warmed through to maintain the crispy topping. Avoid microwaving as it can make the topping soggy.
How to Serve
Serve this delicious recipe with your favorite sides.
FAQs
Can I use canned mushrooms instead of fresh?
Fresh mushrooms provide better texture and flavor, but if you use canned, be sure to drain them well and sauté until any excess moisture evaporates.
What can I substitute for French’s fried onions?
If you don’t have fried onions, crispy fried shallots or homemade panko breadcrumbs toasted with butter make great alternatives for a crunchy topping.
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Best-Ever Green Bean Casserole Recipe
- Total Time: 1 hour 20 minutes
- Yield: 6 servings 1x
- Diet: Vegetarian
Description
This Best-Ever Green Bean Casserole combines fresh green beans with sautéed crimini mushrooms in a creamy, garlicky béchamel sauce topped with crispy French’s fried onions. Baked to bubbling perfection and browned on top, this classic comfort dish offers a flavorful twist with fresh ingredients and rich Parmesan cheese.
Ingredients
Scale
Vegetables
- 2 lb. fresh green beans
- 1 lb. crimini mushrooms, sliced (divided into ½ lb. portions)
- 4 large sprigs thyme (divided into 2 sprigs each)
- 4 garlic cloves, finely grated
Fats & Oils
- 2 Tbsp. extra-virgin olive oil, divided
- 6 Tbsp. unsalted butter, divided
Dairy
- 1¼ cups whole milk
- 1 cup heavy cream
- ½ cup grated Parmesan cheese
Pantry
- Kosher salt
- 2 Tbsp. all-purpose flour
- Freshly ground black pepper
- ¾ cup French’s fried onions
Instructions
- Blanch the Green Beans: Place a rack in the middle of the oven and preheat to 375°F. Bring a large pot of salted water to a boil. Working in batches, cook the fresh green beans until bright green and half tender, about 3 minutes per batch. Drain and allow to cool, then trim the stem ends.
- Sauté Half the Mushrooms: Heat 1 tablespoon of extra-virgin olive oil in a large skillet over medium-high heat. Add half the sliced crimini mushrooms and cook without stirring for 2 minutes to brown the underside. Toss and continue cooking, tossing occasionally, until the mushrooms are browned on both sides, about 3 more minutes. Add 2 tablespoons unsalted butter and 2 sprigs of thyme, tossing occasionally until the butter browns and mushrooms are very tender, about 4 minutes. Season with kosher salt and transfer to a plate.
- Sauté Remaining Mushrooms: Repeat the process with the remaining 2 tablespoons unsalted butter, 1 tablespoon olive oil, the rest of the mushrooms, and thyme sprigs. Season with salt and set aside.
- Make Béchamel Sauce: Melt the remaining 2 tablespoons butter in a large saucepan over medium-low heat. Whisk in 2 tablespoons all-purpose flour and cook until the roux is golden brown and fragrant, about 4 minutes. Gradually whisk in the whole milk and heavy cream, increase the heat, and bring to a simmer while whisking often. Cook until the sauce thickens and bubbles, about 5 minutes. Remove from heat, then whisk in the grated garlic and Parmesan cheese. Season with kosher salt and freshly ground black pepper to taste.
- Assemble and Bake: Arrange the blanched green beans and sautéed mushrooms evenly in a 2-quart baking dish. Pour the béchamel sauce over the vegetables—it may seem a bit thin but will thicken during baking. Cover tightly with foil and bake for 25–30 minutes until the sauce is bubbling.
- Bake Until Golden: Remove the foil and continue baking uncovered for 15–20 minutes until the casserole is lightly browned on top and around the edges.
- Add Fried Onions and Finish Baking: Sprinkle ¾ cup French’s fried onions evenly over the top. Bake for an additional 3 minutes until the onions are slightly darker and fragrant.
- Set Before Serving: Let the casserole sit for 10 minutes to set before serving to allow the sauce to thicken fully and flavors to meld.
Notes
- Blanching the green beans ensures they stay bright and retain a slight crunch after baking.
- Sauté mushrooms in batches to achieve a deeply browned, caramelized flavor.
- The béchamel sauce provides a rich and creamy base, enhanced with garlic and Parmesan for extra depth.
- Covering the casserole during initial baking helps the sauce cook without drying out.
- Allowing the dish to rest after baking improves texture and flavor melding.
- French’s fried onions add a crunchy, savory topping that contrasts beautifully with the creamy interior.
- Prep Time: 20 minutes
- Cook Time: 1 hour
- Category: Casserole
- Method: Baking
- Cuisine: American
Keywords: green bean casserole, mushroom casserole, holiday side dish, baked casserole, creamy green beans
