Mouthwatering Make Ahead Green Bean Casserole is the ultimate holiday side dish — creamy, crispy, and stress-free. Made with tender green beans, a rich mushroom sauce, and crunchy onions on top, this version is crafted for flavor and convenience. Whether you’re hosting Thanksgiving, Christmas, or a Sunday dinner, this make-ahead casserole helps you prep in advance without sacrificing taste.
Table of Contents
Why You’ll Love This Recipe
- ✅ Make it ahead — Save oven space and time on the big day
- 🌱 Fresh ingredients — Skip the canned soup and use real mushrooms
- 👪 Family favorite — A comforting, nostalgic holiday classic
- 🧅 Crispy topping — Golden fried onions that hold up
- 🧄 Customizable — Add cheese, bacon, or herbs to make it your own
Ingredients
For the casserole:
- 1½ lbs fresh green beans, trimmed and halved
- 2 tbsp unsalted butter
- 1 tbsp olive oil
- 1 small yellow onion, diced
- 2 cloves garlic, minced
- 8 oz cremini or button mushrooms, sliced
- ¼ cup all-purpose flour
- 1½ cups whole milk
- ½ cup chicken or vegetable broth
- ½ tsp salt
- ¼ tsp black pepper
- ¼ tsp ground nutmeg (optional)
For topping:
- 1½ cups crispy fried onions (store-bought or homemade)
Instructions
- Blanch the green beans
Bring a large pot of salted water to a boil. Add green beans and cook 3–4 minutes until bright green and just tender. Drain and transfer to an ice bath to stop cooking. Drain again and set aside. - Make the mushroom sauce
In a large skillet, heat butter and olive oil over medium heat. Add onions and sauté for 2–3 minutes. Add garlic and mushrooms; cook until soft and reduced, about 6–8 minutes. - Make it creamy
Sprinkle flour over mushrooms and stir for 1 minute. Gradually whisk in milk and broth. Bring to a simmer and cook until thickened (about 5–6 minutes). Season with salt, pepper, and nutmeg. - Combine & cool
Stir in the green beans until evenly coated. Remove from heat. If making ahead, let the mixture cool completely. - Assemble the casserole
Transfer to a greased 9×13″ baking dish. Cover and refrigerate if prepping ahead. When ready to bake, bring to room temperature, top with crispy onions, and bake at 375°F (190°C) for 25–30 minutes until bubbling and golden.
Recipe Details
- Prep Time: 20 minutes
- Cook Time: 25 minutes
- Total Time: 45–50 minutes
- Servings: 8
Nutrition Facts (per serving, approx.)
- Calories: 210
- Protein: 5g
- Carbs: 18g
- Fat: 14g
- Fiber: 3g
- Sodium: 340mg
Tips & Variations
- Make ahead: Prep the casserole without the onion topping. Refrigerate up to 2 days. Add onions and bake just before serving.
- Use frozen green beans: Thaw and dry well before using.
- Add crunch: Mix crushed Ritz crackers or panko into the topping.
- Cheesy version: Add ½ cup shredded cheddar or gruyère to the sauce.
- Dairy-free? Sub oat milk or unsweetened almond milk + vegan butter.
FAQs
Can I use canned green beans?
Fresh or frozen is best for texture, but canned can work in a pinch. Drain and reduce bake time by 10 minutes.
What if I don’t have fried onions?
Top with toasted panko + parmesan, or homemade shallot crisps.
How do I reheat leftovers?
Cover and bake at 350°F until warm (15–20 minutes). Add extra onions on top for crunch.
Can I freeze green bean casserole?
Yes, but it’s best without the onions. Assemble, freeze, thaw overnight, then top and bake.
Conclusion
This Mouthwatering Make Ahead Green Bean Casserole is a holiday essential you’ll make year after year. Rich, creamy, and packed with flavor, it’s the ideal side dish to prep in advance and bake fresh when guests arrive. With customizable add-ins and crispy golden onions on top, it’s guaranteed to steal the show — right next to the turkey.
Mouthwatering Make Ahead Green Bean Casserole
Equipment
- – Large pot
- – Skillet
- – 9×13” baking dish
- – Mixing spoon & whisk
Ingredients
- **Casserole:**
- – 1½ lbs green beans trimmed
- – 2 tbsp butter
- – 1 tbsp olive oil
- – 1 small onion diced
- – 2 garlic cloves minced
- – 8 oz mushrooms sliced
- – ¼ cup all-purpose flour
- – 1½ cups whole milk
- – ½ cup chicken or vegetable broth
- – ½ tsp salt
- – ¼ tsp pepper
- – ¼ tsp nutmeg optional
- **Topping:**
- – 1½ cups crispy fried onions
Instructions
- Boil green beans for 3–4 mins, then ice bath. Drain.
- Sauté onion, garlic, and mushrooms in butter/oil until soft.
- Stir in flour. Slowly whisk in milk & broth. Simmer to thicken.
- Add green beans. Cool if making ahead.
- Pour into greased dish. Refrigerate or bake immediately.
- Top with fried onions and bake at 375°F for 25–30 mins until golden.
Notes
– Add shredded cheese for extra richness
– Gluten-free? Use GF flour and GF onions