Creamy Green Bean Casserole with Boursin Cheese

This homemade Green Bean Casserole with creamy Boursin cheese is a modern take on the classic holiday side dish. It smothers tender green beans, mushrooms, and onions in a garlicky Boursin cheese-based cream sauce before it’s baked until bubbly and topped with crispy fried onions. No canned soup needed here! 

If you’re ready to take your green bean casserole from “meh” to gourmet, you need this Boursin Green Bean Casserole in your life! With tender-crisp green beans and a creamy mushroom sauce infused with garlic herb Boursin cheese, this easy recipe is designed to simplify your holiday meals without sacrificing satisfaction. 

Now, my grown-up version is a little different than the green bean casserole you ate as a kid. Instead of the canned green beans and canned cream of mushroom soup, I bumped up the flavors with fresh ingredients. I think the extra effort is worth it, but keep reading for my notes if you’re going for convenience instead.

And don’t worry about trying to make this recipe “pretty”. Some dishes are destined to be admired before devouring, and others (like this one) are pure nostalgia without the fancy garnishes and pretty styling. Trust your taste buds, not your eyes!

Why You’ll Love This Boursin Green Bean Casserole Recipe 

• Whether you’re planning Friendsgiving, hosting your family’s holiday feast, or craving a veggie-forward side that feels luxurious, this casserole fits the bill. 
• Assemble it the day before and pop it in the oven while you focus on the more high-maintenance dishes (ahem, turkey). 
• The Boursin melts like a dream into the sauce and adds an instant gourmet flavor. Every bite of this wholesome winter casserole is designed to warm you from the inside out. 

Green Bean Casserole Ingredients

Thanks to fresh produce, a rich Boursin-based cream sauce, and the always-popular fried onion topping, this casserole will disappear almost as soon as it hits the table. 

Here’s everything you’ll need to make it:

• Green beans. Use trimmed fresh green beans for that signature crisp-tender bite. I give them a quick blanch in boiling water, then plunge them into an ice bath to keep the beans vibrant and snappy.
• Butter
• Sliced mushrooms and diced onions. Stick with fresh mushrooms to avoid the soggy texture you often get with canned mushrooms.
• Garlic
• All-purpose flour
• Low-sodium vegetable broth, chicken broth, or chicken stock
• Heavy cream
• White wine vinegar
• Boursin cheese, ​in the Garlic & Fine Herbs flavor
• Fried onions, store-bought or homemade

(full ingredient list and quantities in the recipe card below)​

Street Smart Nutrition Tip: For even cooking and the best texture, try to cut your trimmed green beans into uniform 2-inch pieces. Not only will this help them cook at the same rate, but it also makes the casserole easier to serve. They don’t have to be perfect or exact, but cut the longer green beans in half and say, “good enough!”

Swaps and Substitutions

Whether you’re working with what you have or changing things up for dietary preferences, this creamy green bean casserole is surprisingly flexible.

If you don’t have fresh green beans, or want to save some time, grab a bag of frozen green beans. Make sure to fully thaw them in advance and drain any excess water that melts off. 

Frozen is the next-best option, in my opinion. But if you prefer a softer texture, canned green beans work, too. Since they’re already cooked, skip blanching and just drain and rinse well before using. 

You can also make these easy adjustments based on your taste preferences or dietary needs:

• If you need a gluten-free version, swap the all-purpose flour for a gluten-free flour blend that contains a thickening agent like xanthan gum. Alternatively, you could use a cornstarch slurry with equal parts corn starch + water or broth. Also, be sure to grab gluten-free French-fried onions or make your own.
• If you can’t find Boursin, use whipped cream cheese or goat cheese mixed with a pinch of garlic powder and dried herbs in the creamy sauce instead.
• The vinegar can be replaced with a squeeze of lemon juice.
• Crumbled crispy bacon stirred into the sauce or sprinkled on top (under the fried onions) adds smoky, salty depth and makes these Boursin green beans even better.

Street Smart Nutrition Tip: Taste the sauce before it goes into the baking dish, especially if you’re swapping the cheese, broth, or flour. These small changes can shift the flavor and consistency in a big way.

How to Make Green Bean Casserole with Boursin Cheese

I won’t call this an “easy side dish”…it does take a few extra steps. But your patience and attention to detail will be rewarded! 

Nervous about making the sauce from scratch? Don’t be! Watch this quick video on how to make a light roux. You might never turn to canned cream of mushroom soup again!

Preheat your oven to 375 degrees F and follow these steps: 

1. Bring a large pot of water to a boil. Add the trimmed green beans and cook until they’re tender-crisp (about 2-3 minutes). Immediately transfer them to an ice bath to stop the cooking process.
2. Meanwhile, melt a tablespoon of butter in a large skillet over medium heat. Add the onions and mushrooms, and sauté until soft and fragrant.
3. Stir in the minced garlic, and once fragrant, transfer the mixture to a small bowl.
4. In the same pan, add the remaining butter. Melt over medium-low or low heat. Once melted, sprinkle in the flour, stirring continuously to form a light roux.
5. Slowly stir in the broth and cream. Once mixed, add the vinegar and bring to a low simmer, stirring continuously as it thickens into a creamy gravy (about 4-5 minutes).
6. Stir in the Boursin cheese, and whisk or stir until the cheese is melted. Remove the pan from the heat.
7. Drain the blanched green beans, then dump them into a baking dish. Add back the cooked onion and mushroom mixture.
8. Cover the casserole dish with foil and bake for 45 minutes. Remove from the oven and sprinkle the fried onions on top. Return to the oven, uncovered, and broil for 5 minutes to brown the onions.

Then, simply serve and enjoy! Half the challenge is getting all your recipes finished at the same time. If needed, you can hold the cooked green bean casserole in a hot oven until it’s time to eat. Just don’t add the fried onions right away, otherwise they’ll end up soggy.

Street Smart Nutrition Tip: You’ll know the sauce is thickened when it coats the back of a spoon. Or, it should leave a trail as you drag a spoon or spatula across the bottom of the pan. If you’re used to cream of mushroom soup, it won’t be quite as thick or congealed. But the rich, gravy-like texture should be able to coat the green beans without being overly runny or sauce-like.

What to Serve with Green Bean Casserole

It should come as no surprise that this casserole fits right in on your Thanksgiving dinner or holiday menu. It’s a creamy and flavorful pairing with all the classic mains, like roast turkey, rotisserie chicken, orange glazed ham, prime rib, or stuffed acorn squash. 

Just don’t forget about the rest of the sides. My family gatherings are full of cozy winter vegetables in all their forms. We often pair this green bean casserole recipe with mashed potatoes, candied sweet potatoes, roasted Brussels sprouts or broccoli, or a hearty massaged kale salad.

Honestly, this is one of those dishes that you won’t regret bringing to any cozy dinner party, no matter what’s on the rest of the table.

Storing Leftover Green Bean Casserole 

Once the leftover green bean casserole is cool, transfer it to an airtight container and keep it in the fridge for up to 3-4 days. It also freezes well for up to 2 months. Thaw overnight in the fridge before reheating.

Reheat the leftover casserole in a 350ºF oven until warmed through (about 20 to 25 minutes). For individual portions, microwave them in 30-second intervals until warm. Sprinkle on a fresh handful of fried onions before serving to revive the crunch factor.

Green Bean Casserole FAQS 

Is it better to use frozen or canned green beans for green bean casserole?

Fresh green beans are ideal, but between frozen and canned, I’d go with frozen. Canned green beans will work in a pinch, but they tend to be much softer, and the final dish won’t feel quite as fresh or gourmet. 

Why is my green bean casserole runny?

This can happen if you don’t fully drain the green beans, if there’s not enough flour to thicken the sauce, or if you don’t fully thicken the sauce on the stovetop first. Here’s how you can fix it:

• If it’s just a little runny, let the casserole cool, uncovered, for 5-10 minutes. As steam rises off, the sauce will thicken a bit on its own once it’s no longer bubbling hot straight out of the oven.
• Add a cornstarch slurry. Mix 1 tablespoon of cornstarch with 1 tablespoon of broth or water. Whisk until smooth, no lumps. Then stir it into the green bean casserole and bake for another 10 minutes.

Can I freeze green bean casserole for later?

You sure can, but for the best results, assemble the casserole without the fried onion topping, let it cool completely, then wrap it tightly and freeze for up to 2 months. When you’re ready, thaw it in the fridge overnight, then bake as directed and finish with fresh crispy onions.

Do I have to use MSG?

The MSG is optional, though it does add a deep umami flavor compared to regular table salt. If you’d rather skip it, a dash of salt or a splash of soy sauce will give you a similar flavor.

If this easy green bean casserole with Boursin cheese is everything you dreamed it would be, you’ll also love this Creamy Spinach Rice and this Smoky Sweet Potato Mash. And if this recipe makes an appearance at your Thanksgiving table, I’d love to hear what you think! Leave a comment or rating below.

As always, thanks for stopping by the Street Smart Nutrition blog. Cheers to more fearlessly nourishing meals!