Few Thanksgiving side dishes keep the masses as happy as a homemade green bean casserole. It’s comforting, familiar, and always one of the first dishes to disappear from the table. This version keeps everything you love about the classic—creamy sauce, tender green beans, crispy onion topping—but tweaks it with a few simple upgrades.
First, skip the canned soup. Deeply browned mushrooms napped in a quick Parmesan cream sauce (a.k.a. béchamel) add extra savory depth. You don’t need canned green beans either. Fresh green beans retain more flavor and a more satisfying al dente texture. We’ll concede on one prepared food item, though: Make DIY crispy shallots if you must, but there is a reason French’s Crispy Fried Onions are so iconic—nothing beats them. Best of all, this elevated green bean casserole is easy enough to make on a busy Thanksgiving morning.
Tips for the best green bean casserole
- Brown your mushrooms properly. Don’t salt too soon or crowd the pan (cook them in batches if needed)—both will cause them to steam rather than caramelize.
- Salt your blanching water. Like pasta water, it should taste briny. It’s the best way to season the beans from the inside out.
- Blanch then trim. Trimming the ends of the beans after they’ve been blanched prevents them from soaking up too much water.
- Save a pot. This recipe is written so that you can cook the mushrooms and make the sauce at the same time, but if you’d like, you can whisk up the béchamel in the same pan you used to sear the mushrooms. Just add the butter and flour to the pan after removing the mushrooms, using a spoon to scrape up any browned bits (they will add even more flavor to the casserole), then continue with the recipe as written, adding the milk and cream.
- Don’t overdo the sauce. It will loosen as it bakes, coating every bean in silky goodness.
- Use the right dish. A shallow 2-quart casserole dish ensures even bubbling and the right sauce-to-crunch ratio.
- Make it ahead—partially. You can prep the sauce, cook the mushrooms, and blanch the beans the day before, but the dish is best assembled and baked the day you plan to serve it. Sprinkle on the onions just before serving for maximum crunch.
- Additions: Our reader comments are a trove of great advice. Some suggest adding a spoonful of Dijon mustard to the cream sauce or a few dashes of hot sauce. Others took a shortcut by using frozen green beans (a much better move than using canned if you’re so inclined). You could also trade the parm for cheddar cheese or Gruyère, or go fancy with some wild mushrooms instead of crimini. Point is: this is our favorite green bean casserole; now go make it yours.
Recipe information
Total Time
1 hour 35 minutes
Yield
8 servings
Ingredients
2
2
1
6
4
2
1¼
1
4
½
¾
Need to make a substitution?
Preparation
Step 1
Place rack in middle of oven; preheat oven to 375°. Working in batches, cook 2 lb. fresh green beans in a large pot of boiling salted water until bright green and halfway to tenderness, about 3 minutes per batch. Drain and let cool; trim stem ends.
Step 2
Heat 1 Tbsp. extra-virgin olive oil in a large skillet over medium-high. Cook ½ lb. crimini mushrooms, sliced, without stirring, until golden brown underneath, about 2 minutes. Toss and continue to cook, tossing occasionally, until browned on both sides, about 3 minutes more. Add 2 Tbsp. unsalted butter and 2 large thyme sprigs to pan. Cook, tossing occasionally, until butter browns and mushrooms are dark brown and very tender, about 4 minutes longer. Season with kosher salt and transfer to a plate. Repeat with 2 Tbsp. unsalted butter, salt, and remaining 1 Tbsp. extra-virgin olive oil, ½ lb. crimini mushrooms, sliced, and 2 large thyme sprigs.
Step 3
Melt remaining 2 Tbsp. unsalted butter in a large saucepan over medium-low. Whisk in 2 Tbsp. all-purpose flour and cook, whisking occasionally, until roux is golden brown and smells mildly nutty, about 4 minutes. Whisk in 1¼ cups whole milk and 1 cup heavy cream. Increase heat and bring to a simmer, whisking often, and cook until béchamel sauce is thick and bubbling, about 5 minutes. Remove from heat and whisk in 4 garlic cloves, finely grated, and ½ cup grated Parmesan; season with salt and freshly ground pepper.
Step 4
Arrange green beans and mushrooms in a 2-qt. baking dish. Pour sauce over bean mixture (it may not look like enough, but it will get saucier as it bakes). Cover tightly with foil and bake until sauce is bubbling, 25–30 minutes. Uncover and continue to bake until casserole is lightly browned on top and around the edges, 15–20 minutes longer. Top with ¾ cup French’s fried onions and continue to bake just until onions are slightly darker and fragrant, about 3 minutes. Let sit 10 minutes to set before serving.
Editor’s note: This green bean casserole recipe was first printed in November 2016 as part of BA’s Best, a collection of our essential recipes. Head this way for more of our best Thanksgiving dinner ideas →