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This Boursin cheese green bean casserole is creamy, cheesy, and packed with flavor! It’s made with fresh green beans, a rich and flavorful Boursin cheese sauce, and plenty of crispy fried onions on top.
The best part? No canned soup needed! It’s the perfect side dish for Thanksgiving, Christmas, or any holiday dinner. I love serving this with apple cider glazed ham and baked Mac and cheese!

Table of Contents
I originally wanted to add mozzarella cheese on top, but I’m so glad I didn’t! Between the Boursin cheese and heavy cream, the sauce was already rich and creamy, and adding mozzarella would’ve made it too heavy.
Especially when you’re serving it alongside a bunch of other holiday side dishes! Honestly, it was completely unnecessary because this casserole was perfect as is.
Why You’ll Love This Recipe
- No canned soup! Everything is made from scratch with simple ingredients, and the homemade sauce tastes so much better.
- Incredibly flavorful. The Boursin cheese, Dijon mustard, and seasonings make the sauce absolutely delicious.
- Perfectly creamy. The sauce thickens beautifully and coats the green beans without being too thick or runny.
- Great for the holidays. You can prepare most of it ahead of time, making Thanksgiving or Christmas dinner a little easier.

Ingredient Notes
See the recipe card below for ingredient quantities and complete instructions.
- Fresh green beans: I used 2 pounds of fresh green beans and blanched them before assembling the casserole.
- Boursin cheese: The star ingredient! It melts into the sauce and adds so much flavor. I used the garlic and fine herbs flavor but the shallot and chive flavor works too!
- Dijon mustard: Adds such great flavor.
- Seasonings: Granulated garlic, onion powder, paprika, Italian seasoning, kosher salt, and black pepper.
- Mushrooms: Completely optional. I used fresh shiitake sliced mushrooms but any type of fresh mushrooms work well for this recipe.
- French’s crispy fried onions: Because what’s green bean casserole without those delicious crispy onions?
Can I Make This Green Bean Casserole Ahead of Time?
Absolutely! This is a great recipe to prepare ahead of time, especially if you’re making it for Thanksgiving or Christmas.
You can blanch the green beans and prepare the Boursin cheese sauce up to 24 hours in advance. Let the sauce cool, then store it and the drained green beans separately in airtight containers in the refrigerator.
When you’re ready to bake, gently reheat the sauce on the stovetop over low heat, adding a small splash of chicken stock or heavy cream if it has thickened too much. Combine it with the green beans in your baking dish.
Cover and refrigerate if you’re assembling it a few hours before baking, but don’t add the crispy fried onions until you’re ready to bake.
Since the casserole will be cold, it may need an additional 10–15 minutes in the oven. Bake uncovered at 350 degrees F until hot and bubbly, adding the fried onions during the last 15–20 minutes so they don’t get too dark.

Top Tips
- Don’t skip blanching the green beans. Blanching helps the green beans maintain their beautiful green color and gives them a head start before baking. Just make sure not to overcook them. I boiled them for exactly 5 minutes!
- Season generously with salt and pepper. I can’t stress this enough! The sauce has plenty of flavor from the Boursin cheese and seasonings, but salt and pepper are essential. Taste the sauce before adding it to the green beans and adjust until it’s perfectly seasoned.
- Drain the green beans really well. You don’t want excess water thinning out that delicious creamy sauce.
- Skip the other cheeses. Trust me, I was tempted to add mozzarella all over the top, but it would’ve been overkill. The Boursin sauce is already rich, flavorful, and perfectly thick. When you’re serving this with mashed potatoes, mac and cheese, stuffing, and other holiday favorites, there’s really no need for additional cheese.
- Don’t overbake. Since the green beans are already blanched and the sauce is cooked, 20 minutes in the oven is all you need to heat everything through.

Can I use frozen green beans?
Yes! Fresh green beans are my favorite for this recipe, but frozen green beans will work. Thaw them completely and drain them really well before assembling the casserole. There’s no need to blanch frozen green beans.
Can I use canned green beans?
You can, but I highly recommend fresh green beans for the best texture. Canned green beans are already very soft and may become mushy after baking. If using canned, drain them thoroughly and skip the blanching step.

Watch How I Make This Recipe…
Tried this recipe? Please leave a star ⭐️⭐️⭐️⭐️⭐️ rating in the recipe card below and/or a review in the comments section further down the page. Also, please consider following me on Facebook or Pinterest!

Boursin Cheese Green Bean Casserole
Equipment
- 11×9 Baking Dish
Ingredients
- 2 lbs fresh green beans, trimmed
- 1 cup mushrooms, I used shiitake
- 2 garlic cloves , finely minced
- 3 tablespoons salted butter
- 3 tablespoons all-purpose flour
- 1 cup chicken stock
- 1 ½ cups heavy cream
- 1 package, 5.2 ounces Boursin Garlic & Fine Herbs cheese
- 1 teaspoon Dijon mustard
- 1 teaspoon granulated garlic
- 1 teaspoon onion powder
- 1 teaspoon paprika
- 1 teaspoon Italian seasoning
- Kosher salt and black pepper, to taste
- 3 tablespoons olive oil , for sautéing mushrooms and garlic
- 2 cups French’s crispy fried onions
Instructions
- Preheat your oven to 350 degrees F.
- Bring a large pot of generously salted water to a boil. Add the green beans and blanch for 3–5 minutes, until bright green and slightly tender. Immediately transfer them to an ice bath to stop the cooking process, then drain thoroughly.
- Heat the olive oil in a large skillet over medium-high heat. Add the sliced shiitake mushrooms and cook for a few minutes until softened and lightly browned. Stir in the minced garlic and cook for another 30 seconds, until fragrant. Remove the mushrooms and garlic from the skillet and set aside.
- In the same skillet, melt the butter over medium heat. Add the flour and whisk continuously for 1–2 minutes.
- Slowly whisk in the chicken stock and heavy cream until smooth. Add the Boursin cheese, Dijon mustard, granulated garlic, onion powder, paprika, and Italian seasoning. Cook over medium-low heat, stirring frequently, until the cheese melts and the sauce is perfectly thick and creamy.
- Season generously with kosher salt and black pepper. Taste the sauce and adjust the seasoning as needed. Stir in the blanched green beans and mushrooms. Check for seasoning.
- Add the mixture to an 11×9-inch baking dish and smooth out the top gently.
- Sprinkle the crispy fried onions evenly over the top and bake uncovered for 20 minutes, or until hot and bubbly.
- Serve immediately and enjoy!
Notes
- Make ahead: Blanch the green beans and prepare the sauce up to 24 hours in advance. Refrigerate separately, then gently reheat the sauce, assemble, and bake when ready. Add the crispy onions just before baking.
- Storage: Refrigerate leftovers in an airtight container for up to 3–4 days. Reheat in the oven at 350 degrees F until heated through.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.







