Green Bean Casserole

Classic green bean casserole was a staple at just about every holiday gathering while growing up in Minnesota, but the traditional canned version was never my favorite. But making it from scratch with fresh green beans and a creamy homemade mushroom sauce has completely changed my opinion. This version is so flavorful and a classic vegetable side dish I actually look forward to serving.

Key Ingredients And Substitutions

I tested a few different versions of this casserole recipe before landing on this winner. Here are my notes about why I chose each ingredient for my green bean casserole recipe:  

• Fresh green beans: I recommend fresh green beans over canned green beans for the best texture. They hold their shape beautifully and have a much fresher flavor than canned or frozen beans. Trim the ends and cut them in half for easier serving.
• Butter: A little butter provides a base fat for sautéing the vegetables while also adding flavor in a way that oil can’t. Salted or unsalted butter both work.
• Yellow onion: I like yellow onions for the little sweetness and savory flavor they add to my homemade mushroom sauce. Finely chopping it helps it blend into the sauce.
• Garlic: Freshly minced garlic provides another layer of flavor that pairs especially well with the mushrooms.
• Mushrooms: Baby bella or white button mushrooms are both great choices. Baby bellas have a slightly deeper, earthier flavor, while white button mushrooms offer a milder, more traditional mushroom taste. I finely chop the mushrooms so they distribute throughout the sauce rather than leaving large mushroom pieces.
• All-purpose flour: This is the thickening agent for the homemade sauce. A gluten-free 1:1 flour blend can be substituted.
• Chicken broth: Adds savory flavor and helps create the base of the sauce. Vegetable broth works equally well for a vegetarian version.
• Half-and-half: Gives the mushroom sauce its creamy consistency without making it overly heavy. Whole milk or heavy cream can work in a pinch, though the sauce may be slightly thinner or thicker.
• Soy sauce: This is my little secret ingredient! Just one teaspoon adds the perfect amount of umami and makes the mushroom sauce taste richer and more savory. And it doesn’t make the sauce taste like soy sauce either. Use tamari for a gluten-free option. I would skip coconut aminos here since their natural sweetness could throw off the savory flavor.
• French fried onions: The classic crispy shallots topping is a must for green bean casserole. I use store-bought French fried onions to keep things easy, and gluten-free versions are available.

Find the ingredient list with exact measurements in the recipe card below.

How To Make This Creamy Casserole

My homemade green bean casserole comes together in a few simple steps. The biggest difference from traditional recipes is that the green beans are blanched separately and the mushroom sauce is made from scratch on the stovetop before everything goes into the oven.

1. Blanch the green beans. Bring a large pot of salted water to a boil and cook the green beans just until they’re tender and bright green. Immediately transfer them to an ice bath to stop the cooking process. This step is important so that the beans don’t get mushy in the finished casserole. 
2. Start the mushroom sauce. Melt the butter in a large skillet, then sauté the onions, mushrooms, and garlic until softened. Sprinkle the flour over the mushroom mixture and stir until everything is evenly coated. Continue cooking for 2-3 minutes, stirring constantly. This step is important so don’t rush it! Cooking the flour briefly before adding the liquid helps eliminate its raw flour taste and creates a smooth, creamy sauce.
3. Finish the sauce. Slowly stir in the broth, followed by the half-and-half, and then the soy sauce. Let the mixture gently simmer until it thickens enough to coat the back of a spoon. 
4. Assemble the casserole. Add the drained tender green beans to a greased 9×13-inch casserole dish. Pour the mushroom sauce over the top and stir until the beans are evenly coated.
5. Bake uncovered. Bake at 375°F for 20 minutes. I intentionally leave the casserole uncovered during this first bake to help preserve the texture of the green beans.
6. Add the crispy topping. Remove the casserole from the oven, give everything a stir, and sprinkle the French fried onions evenly over the top. Return to the oven for a few minutes, until the sauce is bubbling and the onions are golden brown. Let the casserole rest for about 5 minutes before serving. The sauce will settle and thicken slightly as it cools.

For serving size and the complete directions and ingredient amounts, scroll down to the recipe card below. All of our recipes include the nutrition analysis, listing calories (kcals), protein, carbohydrates/carb, fiber, sugar, sodium, cholesterol, and more per serving.

Make It Gluten Free

This green bean casserole is easy to make gluten-free with three simple substitutions:

• Flour: Swap the all-purpose flour for a gluten-free 1:1 baking flour blend.
• Soy sauce: Use tamari instead of regular soy sauce. Tamari offers a similar savory, umami-rich flavor and is typically gluten-free (check the label).
• French fried onions: Check the label and choose certified gluten-free French fried onions, such as MaeMai or Feel Good Foods brands. 

Make It Vegetarian Or Vegan

For a vegetarian version, use vegetable broth instead of chicken broth. And for a vegan green bean casserole, use vegetable broth, then use plant-based stick butter instead of dairy butter. And check the label to ensure the fried onions are vegan, too. 

Complete Your Holiday Table

Green bean casserole deserves a spot alongside all the other holiday side dishes. I love serving it as a traditional Thanksgiving side dish right alongside the roasted turkey for Thanksgiving dinner. But it pairs just as nicely with other foods and more casual fall dinners, too.

I’ve made it to serve with this crockpot pork roast, this sheet pan Caesar chicken, and this chili cornbread casserole as an alternative to sauteed green beans or roasted green beans. And I also love to make it for other holiday meals, like when I’m serving my glazed ham for Christmas dinner and Easter. 

Make-Ahead Tips And Leftovers

A little advance prep can make holiday cooking much easier, especially when oven space is limited.

• Make the mushroom sauce ahead: The homemade creamy mushroom sauce can be prepared up to 2 days in advance. Let it cool, transfer it to an airtight container, and refrigerate. When ready to assemble the casserole, gently warm the sauce on the stovetop, stirring until smooth. If it has thickened too much in the refrigerator, add a small splash of broth or half-and-half to loosen it.
• Blanch the green beans ahead: The green beans can also be blanched, cooled in an ice bath, and refrigerated for up to 2 days. Make sure they’re thoroughly drained and patted dry before assembling the casserole.
• Assemble before baking: For the best texture, I don’t recommend to make green bean casserole ahead of time from start to finish. However, the green beans and sauce can both be prepped separately and stored up to 3 days in the fridge, then assembled prior to baking. This helps keep the beans from sitting in the sauce and softening.
• Store and reheat leftovers: Transfer leftover casserole to an airtight container and refrigerate for up to 4 days. Reheat individual portions in the microwave or warm a larger portion in a 350°F oven until heated through. The fried onion topping will soften during storage, so adding a few fresh French fried onions before reheating or serving is a nice way to bring back some crunch.

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The photos in this post were taken by Megan McKeehan.

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