Pin A nostalgic, creamy side dish featuring tender green beans, savory mushrooms, and crispy fried onions—a classic for holiday feasts and family dinners.
This casserole always brings back warm memories of festive dinners at my grandparents' house. The aroma of baking mushrooms and onions filled the kitchen and everyone, young to old, eagerly awaited that golden-topped dish emerging from the oven.
Ingredients
- Fresh green beans: 900 g (2 lb), trimmed and cut into 5 cm (2-inch) pieces (or 900 g frozen green beans, thawed and drained)
- Unsalted butter: 2 tbsp
- Cremini or button mushrooms: 250 g (9 oz), sliced
- Yellow onion: 1 small, finely chopped
- Garlic cloves: 2, minced
- All-purpose flour: 2 tbsp
- Whole milk: 240 ml (1 cup)
- Heavy cream: 120 ml (½ cup)
- Low-sodium vegetable broth: 120 ml (½ cup)
- Salt: 1 tsp
- Black pepper: ½ tsp
- Ground nutmeg (optional): ½ tsp
- Crispy fried onions: 150 g (1½ cups), store-bought or homemade
Instructions
- Prepare the oven:
- Preheat oven to 180°C (350°F).
- Cook the green beans:
- Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender. Drain and rinse under cold water.
- Make the sauce:
- In a large skillet over medium heat, melt butter. Add mushrooms and cook for 5-6 minutes. Add onion and garlic, cooking for 2-3 minutes more.
- Add dry ingredients:
- Stir in flour and cook for 1 minute. Gradually whisk in milk, cream, and broth. Simmer until thickened, about 5 minutes. Season with salt, pepper, and nutmeg.
- Combine and assemble:
- Add green beans to skillet, toss to coat. Transfer mixture to a 2-liter baking dish. Sprinkle half fried onions on top.
- Bake:
- Bake for 25 minutes until bubbling. Top with remaining onions. Bake for 5-7 minutes more until golden.
- Finish:
- Let cool 5 minutes before serving.
Pin 
Every Thanksgiving, someone in our family volunteers to bring this casserole and it never lasts past the first round of servings. Even the kids love helping sprinkle the fried onions at the end!
Preparation and Cooking Tips
Use fresh or frozen green beans—fresh lends extra vibrant color and texture. Slice mushrooms evenly to ensure they brown nicely and enhance the umami depth of your casserole.
Serving Suggestions
Pair with roast turkey, chicken, or serve as part of a vegetarian feast. This side dish holds its own next to mashed potatoes and cranberry sauce.
Variations
Stir in grated cheddar or Gruyère cheese to the sauce for a richer result. For extra crunch, add homemade fried onions just before serving.
Pin Green bean casserole brings classic comfort to any table with its creamy sauce and crispy onion finish. Make it ahead to save time on busy holidays and watch it become a crowd favorite!
Recipe Questions & Answers
- → Can I use frozen green beans?
Yes, thawed and drained frozen green beans work well. Just skip the blanching step for convenience.
- → How can I make this dish ahead?
Assemble through the sauce and green bean step, refrigerate, then add fried onions and bake when ready to serve.
- → Is there a way to make this gluten-free?
Substitute gluten-free flour and confirm store-bought fried onions are gluten-free before using.
- → What cheeses work well in this casserole?
Sharp cheddar or Gruyère can be added to the sauce for enhanced depth and richness of flavor.
- → Can I use different mushrooms?
Cremini or button mushrooms are classic, but portobello or shiitake offer unique flavors and textures.
- → What goes well with this dish?
It pairs best with roasted turkey, chicken, or other hearty mains for festive family meals.