Go Back
Adam

BA’s Best Green Bean Casserole | From-Scratch Holiday Side

Green bean casserole is one of those iconic holiday dishes that shows up on nearly every Thanksgiving table. But this BA’s Best Green Bean Casserole is a serious upgrade from the canned-soup version. With fresh green beans, sautéed crimini mushrooms, garlic, thyme, and a homemade creamy sauce, it’s rich, flavorful, and indulgent without being heavy. Finished with crispy fried onions and a sprinkle of Parmesan, this dish delivers the perfect balance of freshness, creaminess, and crunch. Serve it at your next holiday meal, and you may never go back to the old version again.
Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 40 minutes
Total Time 1 hour
Servings: 10 side portions
Ingredients Equipment Method Notes

Ingredients
  

  • 2 lb green beans trimmed
  • 1 lb crimini mushrooms sliced
  • 4 garlic cloves minced
  • 4 sprigs fresh thyme
  • 2 tbsp all-purpose flour
  • 2 tbsp olive oil
  • 6 tbsp unsalted butter
  • 1 ¼ cups whole milk
  • 1 cup heavy cream
  • ½ cup Parmesan cheese grated
  • ¾ cup French’s fried onions
  • Kosher salt to taste
  • Freshly ground black pepper to taste

Equipment

  • Large pot (for blanching beans)
  • Large skillet
  • Wooden spoon or spatula
  • Strainer/colander
  • Baking dish (9x13-inch or similar)
  • Whisk
  • Oven

Method
 

Step 1: Blanch green beans
  1. Bring a large pot of salted water to a boil. Add green beans and cook for 3–4 minutes until bright green and slightly tender. Drain and immediately transfer to a bowl of ice water to stop cooking. Drain again and set aside.
Step 2: Cook mushrooms and aromatics
  1. In a large skillet, heat olive oil and 2 tbsp butter over medium heat. Add mushrooms and cook until browned, about 6–8 minutes. Stir in garlic and thyme; cook for 1 minute until fragrant.
Step 3: Make the sauce
  1. Add remaining 4 tbsp butter to the skillet. Once melted, stir in flour and cook for 1–2 minutes to form a roux. Slowly whisk in milk and cream. Cook until mixture thickens, about 5 minutes. Stir in Parmesan. Season with salt and pepper.
Step 4: Assemble casserole
  1. In a baking dish, combine green beans and mushroom sauce. Mix gently until beans are evenly coated.
Step 5: Top and bake
  1. Sprinkle fried onions over the top. Bake at 375°F (190°C) for 20–25 minutes, until bubbly and golden.
Step 6: Serve
  1. Let cool slightly before serving.

Notes

🧊 Storage & Reheating
Store leftovers covered in the fridge for up to 3 days.
Reheat in the oven at 350°F for 15–20 minutes until hot.
Can be made 1 day ahead (assemble without onions, refrigerate, then bake with onions before serving).
Not freezer-friendly (cream sauce may split).
🥄 Variations
Cheesy Version: Add Gruyère or cheddar to the sauce.
Nutty Twist: Sprinkle toasted almonds on top with the onions.
Herb Upgrade: Add rosemary or sage for a holiday vibe.
Lighter Option: Use half-and-half instead of heavy cream.
Vegan Swap: Use plant-based milk/cream and vegan fried onions.
❓ 10 FAQs
Can I use canned green beans? – Fresh is best for texture, but canned works in a pinch.
Do I have to use French’s onions? – They’re traditional, but homemade crispy shallots are delicious.
What mushrooms work best? – Crimini add richness, but button or mixed mushrooms are fine.
Can I make this gluten-free? – Yes, use GF flour and gluten-free crispy onions.
Why blanch the beans first? – It keeps them vibrant and prevents overcooking.
Can I prepare it ahead? – Yes, assemble without onions, refrigerate, then bake before serving.
Can I freeze it? – Not recommended (cream sauce may separate).
Can I add more cheese? – Absolutely, Parmesan, Gruyère, or mozzarella all work.
How do I prevent a watery casserole? – Drain beans well and let sauce thicken fully.
Is it very rich? – Yes, but balanced by the fresh green beans and herbs.
🏁 Conclusion
This BA’s Best Green Bean Casserole is creamy, fresh, and packed with flavor. By skipping the canned soup and making everything from scratch, you’ll get a holiday side that’s both comforting and elevated.
Serve it with turkey, ham, or any festive main dish, and it’s sure to become a Thanksgiving (or Christmas!) tradition in your home.