Name: Creamy Green Bean Casserole Recipe
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: 1 lb fresh green beans ends trimmed and beans cut into 2 inch pieces (4 cups); ⅓ cup salted butter; ½ cup finely chopped onion; 1 tablespoon minced garlic; 8 oz white-button mushrooms sliced or chopped into small pieces; ⅓ cup all-purpose flour; 1 cup chicken broth; ½ cup whole milk; ½ cup heavy cream; 1 teaspoon table salt; ½ teaspoon ground black pepper; ¼ teaspoon dried thyme; 2 cups French fried onions

If you're craving a classic side that's everyone's favorite, you're going to love this Creamy Green Bean Casserole Recipe. It’s rich, comforting, and perfectly crispy on top—just what your holiday table or weeknight dinner needs.

A white baking dish filled with a green bean casserole shows three layers: the bottom layer with creamy white sauce mixed with green beans, the middle layer is whole green beans that are bright green and slightly shiny, and the top layer is a thick, crispy, golden-brown fried onion topping that covers the casserole evenly. A golden spoon is scooping from the right side, catching both the crispy onions and green beans. The dish sits on a white marbled surface with a blue and white cloth partially visible on the left side. Photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Creamy Green Bean Casserole Recipe
Top Tip
How to Serve Creamy Green Bean Casserole Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Creamy Green Bean Casserole Recipe

Why You'll Love This Recipe

Every time I make this casserole, it disappears from the table faster than I'd expect. It’s the kind of recipe that feels like a warm hug, combining fresh crisp green beans with that luscious mushroom sauce and the irresistible crunch of fried onions.

Freshness that pops: Using fresh green beans keeps the casserole bright and flavorful, not mushy.
Rich, yet approachable: The creamy mushroom sauce feels indulgent but is easy enough for any weeknight.
Easy prep: You can whip this up in about 45 minutes, making it perfect for last-minute dinners.
Texture perfection: The topping of crispy French fried onions adds that crave-worthy crunch everyone loves.

Ingredients & Why They Work

Choosing the right ingredients makes all the difference with this green bean casserole. Fresh green beans are key for that perfect snap, and I always reach for button mushrooms because they cook down beautifully without overpowering the sauce.

Flat lay of fresh green beans trimmed and cut into pieces, a small slab of salted butter, finely chopped white onion in a neat pile, a small heap of minced garlic, sliced white-button mushrooms, a small bowl of all-purpose flour, small white ceramic bowls holding chicken broth, whole milk, and heavy cream, a small white bowl with table salt, another with ground black pepper, a tiny bowl containing dried thyme, and a mound of crispy French fried onions, all arranged symmetrically on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997

Fresh green beans: Trimmed and cut to bite-sized pieces, they keep the texture bright and tender.
Salted butter: Adds richness and helps soften the onions for a sweet base.
Finely chopped onion: Provides a gentle sweetness and depth of flavor.
Minced garlic: Just enough to add aroma and a subtle kick.
White-button mushrooms: Their mild earthiness blends perfectly into the creamy sauce.
All-purpose flour: It’s the secret to a silky, thickened sauce without any lumps.
Chicken broth: Adds savory depth that complements the mushrooms.
Whole milk: Balances the cream for a smooth texture without being too heavy.
Heavy cream: Gives the sauce that luscious, velvety finish everyone loves.
Table salt: Enhances all the flavors harmoniously.
Ground black pepper: Adds a mild, warming spice.
Dried thyme: A subtle herbaceous note that brightens the sauce.
French fried onions: The crispy, golden topping that makes this dish unforgettable.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

One of the best things about this Creamy Green Bean Casserole Recipe is how easily you can tailor it to suit your taste or dietary preferences. Whether you want to lighten it up or add a little extra flavor, there are plenty of delicious ways to make it your own.

Vegetarian variation: Simply swap the chicken broth for a rich vegetable broth to keep it fully vegetarian without sacrificing that comforting, creamy texture. I’ve tried this version many times during the holidays, and it’s just as satisfying!
Use seasonal mushrooms: Try substituting white-button mushrooms with cremini or shiitake mushrooms for an earthier, deeper flavor that really elevates the sauce.
Make it lighter: If you want a lighter sauce, replacing the heavy cream and whole milk with 1 cup of half-and-half works beautifully—still creamy, but a bit less rich.
Frozen or canned green beans: When fresh green beans aren’t in season, frozen or canned options are totally fine. Just skip the blanching step for a quicker prep.
Add a crunch twist: Mix in some toasted pecans or slivered almonds with the French fried onions for an extra layer of texture and nutty flavor.

Step-by-Step: How I Make Creamy Green Bean Casserole Recipe

The image shows a white plate on a white marbled surface holding a heap of green bean casserole. The dish has green beans as the base layer, covered with a smooth, creamy white sauce. On top, there are many crispy, golden-brown fried onion bits scattered unevenly. The background is softly blurred but shows a white bowl filled with more of the same casserole, placed slightly to the right. Photo taken with an iphone --ar 2:3 --v 7

Step 1: Preheat the oven and prep your green beans

Start by preheating your oven to 350°F (175°C) so it’s ready when your casserole is assembled. Next, blanch the green beans by boiling them in salted water for 5 minutes. This step brightens their color and softens them just right without losing that satisfying bite. Immediately plunge them into an ice bath to stop the cooking – you’ll notice the beans stay vibrantly green and crisp. Set these aside while you move on to the sauce.

Step 2: Build your creamy mushroom sauce

In a large skillet over medium heat, melt ⅓ cup salted butter. Toss in the finely chopped onion and cook for about 3 to 5 minutes until it’s softened and translucent—this is when your kitchen starts to smell amazing!

Next, stir in the minced garlic and let it cook just 30 seconds until fragrant—don’t let it burn here or the sauce will taste bitter. Then add your sliced mushrooms and cook for 5 to 7 minutes, stirring frequently. The mushrooms will release their moisture and reduce nicely, creating the perfect base for your sauce.

Sprinkle the flour over everything and stir well. Cook it for another 30 seconds to 1 minute to toast the flour slightly—this boosts the flavor and helps thicken your sauce perfectly.

Step 3: Whisk in liquids and seasonings for that perfect creamy texture

Slowly drizzle in 1 cup chicken broth while stirring constantly to avoid lumps. Then add ½ cup whole milk, ½ cup heavy cream, 1 teaspoon salt, ½ teaspoon black pepper, and ¼ teaspoon dried thyme. Keep stirring frequently until the sauce thickens enough to coat the back of a spoon—it usually takes about 3 to 5 minutes. This is when everything starts coming together beautifully.

Step 4: Combine green beans with the sauce

Drain the green beans from their ice bath completely, then gently fold them into your creamy mushroom sauce. Make sure every piece is well coated — this is what makes the casserole so irresistibly luscious.

Step 5: Assemble and bake to bubbly, golden perfection

Spread the green bean mixture evenly into a 2-quart baking dish. Sprinkle the top generously with 2 cups of French fried onions to get that signature crispy topping everyone loves.

Pop the casserole onto the center rack of your preheated oven and bake uncovered for 30 minutes. Look for bubbling around the edges and a gorgeous golden brown crust on top — then you know it’s ready to come out and be devoured.

Top Tip

These handy tips will help you nail the perfect Creamy Green Bean Casserole Recipe every time, making sure it’s rich, flavorful, and beautiful on your table.

Blanch green beans properly: I always make sure to shock the green beans in an ice bath right after boiling. This keeps their bright green color and crisp-tender texture—a real game changer for freshness.
Sauté mushrooms slowly: Cooking mushrooms over medium heat until most moisture evaporates really concentrates their flavor. Skipping this step can leave your sauce watery and bland.
Toast the flour: I never rush the flour cooking step. Toasting it lightly with the veggies adds a subtle depth to the sauce that you wouldn’t get otherwise.
Don’t add fried onions too early: Adding the French fried onions only at the very end before baking keeps them crisp and golden rather than soggy.

How to Serve Creamy Green Bean Casserole Recipe

A black cast iron pan filled with cooked green beans covered in a thick creamy white sauce that also has small pieces of light brown mushrooms and some golden crunchy bits on top; a wooden spoon rests in the pan, partly submerged in the sauce, with the handle extending out to the right side; the pan is set on a white marbled surface; photo taken with an iphone --ar 2:3 --v 7

Garnishes

For an extra touch of color and flavor, sprinkle freshly chopped parsley or chives on top right after baking. A little squeeze of fresh lemon juice can also brighten up the creamy sauce beautifully without overpowering it.

Side Dishes

This casserole pairs wonderfully with classic holiday mains like roasted turkey or glazed ham. It’s also a cozy match alongside garlic mashed potatoes, baked sweet potatoes, or a simple quinoa pilaf for a meatless meal.

Make Ahead and Storage

Storing Leftovers

Once baked, cover the casserole tightly and store it in the refrigerator for up to 5 days. When you're ready to enjoy the leftovers, they’ll still taste great, though the green beans will be softer after reheating.

Freezing

Freezing this casserole is not recommended, as it can negatively affect the texture and flavor, making the creamy sauce separate and the green beans mushy.

Reheating

Warm up individual servings in the microwave or reheated the whole casserole in a 350°F (175°C) oven until heated through. Keep in mind the texture will soften a bit after reheating, so treat leftovers gently.

Frequently Asked Questions:

Can I use frozen or canned green beans instead of fresh?

Absolutely! For frozen green beans, simply thaw and drain 4 cups before adding them to the sauce, and skip the blanching. For canned green beans, drain well and also skip blanching. Either way, you’ll still get delicious results.

What can I substitute for heavy cream and whole milk?

You can replace the heavy cream and whole milk with 1 cup of half-and-half for a lighter sauce that still tastes creamy and smooth.

How far ahead can I prepare this casserole?

You can prepare the casserole through the step where the green beans are combined with the sauce, then let it cool and refrigerate for up to 3 days. Add the French fried onions right before baking.

Why do the French fried onions go on top right before baking?

Adding them at the very end ensures they stay crispy and golden after baking, giving the casserole a perfect crunchy topping rather than a soggy one.

Final Thoughts

Making this Creamy Green Bean Casserole Recipe from scratch brings a warm, nostalgic comfort to any meal. I love how the fresh green beans, silky mushroom sauce, and crispy onions come together for a dish that’s both simple and special. Whether it’s for a holiday feast or a cozy weeknight, this casserole is sure to become a favorite on your table. Enjoy every creamy, crunchy bite!