Best-Ever Green Bean Casserole Recipe — Easy Holiday Side

There’s something about the smell of bubbling cream and toasted onions that instantly takes me back to family dinners. My grandmother made a version of green bean casserole every Thanksgiving, but over the years I tweaked it — using fresh blanched green beans, sautéed mushrooms, and a rich, creamy mushroom sauce — until it felt like the best of both tradition and home-cooking. I love this Best-Ever Green Bean Casserole because it’s comforting, easy to scale for a crowd, and always disappears first from the buffet. Green bean casserole also has a cozy place in American holiday history: the classic canned-soup version became popular in the mid-20th century, but using fresh ingredients elevates the flavor and texture while honoring that nostalgic dish.

Who is this recipe for?

• Busy home cooks and holiday hosts who want a reliably delicious side that’s simple to make and impressive on the table.

Core ingredients overview:

• This dish combines fresh green beans, mushrooms, onion, butter, flour, milk (or cream), and crunchy fried onions to create a creamy, flavorful, and comforting holiday side.

Tools & Ingredients

Tools (you’ll need):

• 9×13-inch (or 2-quart) baking dish
• Large pot for blanching
• Large skillet
• Mixing bowls
• Measuring cups and spoons
• Whisk
• Chef’s knife and cutting board
• Colander
• Oven mitts

Ingredients (with short benefits):

• 1.5 lb fresh green beans, trimmed and halved – crisp texture and vibrant color; fresher flavor than canned
• 3 tbsp unsalted butter – adds richness and helps sauté vegetables
• 1 medium yellow onion, finely diced – builds savory sweetness and depth
• 8 oz mushrooms, sliced (cremini or white) – earthy umami that amplifies the sauce
• 2 cloves garlic, minced – brightens and enhances savory notes
• 2 tbsp all-purpose flour – thickens the sauce for a creamy coating
• 1 cup low-sodium chicken stock (or vegetable stock) – adds savory base without overpowering
• 1 1/2 cups whole milk (or half-and-half for richer sauce) – creates the creamy texture
• 1/2 cup sour cream (optional) – lends tang and extra creaminess
• 1 tsp Worcestershire sauce – deep umami boost
• 1 tsp soy sauce (low-sodium) – enhances savory flavor
• 1/2 tsp dried thyme (or 1 tsp fresh chopped) – herbaceous warmth
• Salt and freshly ground black pepper – balances and seasons
• 1 1/2 cups crispy fried onions (store-bought or homemade) – provides crunchy, golden topping
• 1/2 cup shredded cheddar (optional) – adds melty, savory richness for extra indulgence

Instructions:

1. Preheat the oven to 350°F (175°C) and butter or spray a 9×13-inch baking dish.
2. Bring a large pot of salted water to a boil. Add the trimmed green beans and blanch for 3–4 minutes until bright green and just tender. Immediately transfer to a bowl of ice water to stop cooking; drain and set aside.
3. In a large skillet over medium heat, melt the butter. Add the diced onion and sauté for 4–5 minutes until translucent.
4. Add the sliced mushrooms and cook 5–7 minutes until they release their moisture and begin to brown. Stir in the garlic and cook 30 seconds until fragrant.
5. Sprinkle the flour over the vegetables and cook, stirring constantly, for 1 minute to remove the raw flour taste.
6. Gradually whisk in the chicken or vegetable stock, then add the milk (or half-and-half). Bring the mixture to a gentle simmer, whisking so the sauce thickens and becomes smooth, about 3–4 minutes.
7. Stir in the sour cream (if using), Worcestershire sauce, soy sauce, thyme, and adjust salt and pepper to taste. If using cheddar, stir in now for a melty finish.
8. Combine the blanched green beans with the mushroom sauce in a large bowl, tossing until evenly coated. Transfer the mixture to the prepared baking dish and smooth the top.
9. Sprinkle the crispy fried onions evenly over the casserole.
10. Bake in the preheated oven for 20–25 minutes until bubbly and heated through. If you want a deeper golden top, broil for 1–2 minutes while watching closely.
11. Remove from the oven and let rest for 5 minutes before serving.

FAQ
Q: Can I freeze this recipe?
A: Yes. Assemble the casserole (without the fried onions on top), cover tightly, and freeze for up to 2 months. Thaw overnight in the refrigerator before baking, then add the crispy onions just before baking for best texture.

Q: What can I use instead of fresh green beans?
A: You can use frozen green beans (no need to blanch; thaw and pat dry) or canned green beans (drain well and pat dry). Fresh gives the best texture, but frozen is a convenient and tasty alternative.

Q: Can I make this dairy-free or vegetarian?
A: Use unsalted vegetable stock and swap milk/half-and-half for a plant-based milk (choose an unsweetened, creamy option like oat milk). Replace butter with olive oil or vegan butter and use dairy-free fried onions if needed.

Q: How can I make the topping extra crunchy?
A: Reserve about 1/2 cup of the fried onions and stir them into the casserole mixture before baking, then top with the remaining onions just before baking to maintain crunch.

Tips & Tricks

• Blanch green beans just long enough to become bright green and slightly tender; overcooking will make them mushy in the oven.
• Cook mushrooms until nicely browned — that caramelization adds rich flavor to the sauce.
• If the sauce seems too thin, simmer a few extra minutes; if too thick, thin with a splash of milk or stock.
• For the crunchiest topping, add the fried onions in two stages: half mixed into the filling and the rest sprinkled on top right before baking.

Conclusion

If you want additional step-by-step inspiration or variations, see this Best-Ever Green Bean Casserole With Step-by-Step Video Recipe for a detailed video walkthrough. For a classic take and tips on using canned vs. fresh ingredients, check out this Green Bean Casserole guide. If you prefer a Southern-style spin with extra savory notes, this Ultimate Green Bean Casserole – Southern Bite has useful variations.

Enjoy this cozy, crowd-pleasing Best-Ever Green Bean Casserole — share it with family and friends!