Save 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 was one of the first things I learned to cook for our annual family Thanksgiving. Now, it gets requests from kids and grown-ups alike each year.
Ingredients
- Fresh green beans: 900 g (2 lb), trimmed and cut into 5 cm (2-inch) pieces (or substitute with 900 g frozen cut 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 (1⁄2 cup)
- Low-sodium vegetable broth: 120 ml (1⁄2 cup)
- Salt: 1 tsp
- Black pepper: 1⁄2 tsp
- Ground nutmeg (optional): 1⁄2 tsp
- Crispy fried onions: 150 g (1⁄2 cups), store-bought or homemade
Instructions
- Preheat oven:
- Preheat oven to 180°C (350°F).
- Blanch green beans:
- Bring large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender and bright green. Drain and rinse under cold water. Set aside.
- Sauté vegetables:
- In large skillet over medium heat, melt butter. Add mushrooms and cook 5-6 minutes until tender and browned. Add onion and garlic and cook 2-3 minutes more until softened.
- Make sauce:
- Stir in flour and cook 1 minute, stirring constantly. Gradually whisk in milk, cream, and broth. Bring to simmer and cook until thickened, about 5 minutes. Season with salt, pepper, and nutmeg (if using).
- Combine beans and sauce:
- Add drained green beans to skillet and toss to coat evenly.
- Assemble casserole:
- Transfer mixture to 2-liter baking dish. Sprinkle half crispy fried onions on top.
- Bake:
- Bake for 25 minutes until bubbling. Remove, top with remaining onions, and bake for 5-7 minutes more until golden and crisp.
- Rest:
- Let cool for 5 minutes before serving.
Save Every holiday, our green bean casserole is the dish my grandfather insists on, and the grandkids request extra crispy onions. It brings everyone together for seconds.
Make It Ahead
Assemble up to baking and refrigerate covered for up to 24 hours. Add onions and bake before serving for a fresh, crispy topping.
Pairings
This casserole pairs beautifully with roast turkey, chicken, or even vegetarian mains. Its creamy texture balances out savory meats for any festive table.
Allergen Information
Milk, wheat, and possible soy are present. Double-check packaged fried onions and broth for hidden ingredients if you have allergies.
Save This old-school casserole will have everyone reaching for seconds, especially with those crispy onions. Make it ahead to save time on busy holiday mornings.
Recipe FAQ
- → Can I use frozen green beans instead of fresh?
Yes, thawed and drained frozen cut green beans work well and maintain texture similar to fresh.
- → How do I make the sauce creamy and thick?
Cooking flour with butter before adding milk, cream, and broth allows the sauce to thicken smoothly while developing rich flavor.
- → What can I add for extra richness?
Incorporating grated sharp cheddar or Gruyère into the sauce adds depth and a savory boost.
- → How do I keep the fried onions crispy?
Add half the crispy onions before baking and sprinkle the rest near the end to maintain crunchiness and golden color.
- → Is this dish suitable for vegetarians?
Yes, it contains no meat and uses vegetable broth, making it vegetarian-friendly.
- → Can I prepare this in advance?
Assemble through step six, refrigerate up to 24 hours, then add onions and bake just before serving.