Jazz up your Green Bean Casserole with Parmesan Fried Onion crunchy topping for this year’s holiday table. The trouble with green bean casserole is that the version most of us grew up on turns gray and soggy by the time it reaches the table, and that’s the one people push around their plates. I build mine with fresh beans and an irresistible crunchy topping that’s packed with flavor.
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Why You’ll Love This Recipe
- Fresh beans blanched briefly and shocked in ice water have a real snap, so the casserole has texture instead of turning to mush.
- The sauce starts from condensed cream of mushroom soup but gets built up with sauteed onion, garlic, Dijon, thyme, cream, and Parmesan, so it tastes like more than the can it came from.
- Most of the fried onions go on at the very end, so the top stays crunchy through the bake instead of steaming soft under the foil.
- It feeds eight and can be assembled a day ahead, which is exactly what you want when the oven is already full on a holiday.
- Dijon and dried thyme give it a savory backbone without making it taste like mustard.
Ingredients You’ll Need
Here’s what’s worth a note before you start; the printable card below has the full list with quantities.
- Fresh green beans: trim them and blanch for two minutes, then move them straight to ice water so they keep their color and snap. Dry them well afterward, since water clinging to the beans is the fastest way to a watery casserole.
- Condensed cream of mushroom soup: this is the shortcut the dish is built on, and it gives the sauce its body without making a roux from scratch. Two 10.5-ounce cans coat two pounds of beans.
- Heavy cream: a quarter cup smooths the soup out and loosens it into a sauce that coats the beans evenly rather than sitting claggy and thick.
- Dijon mustard and dried thyme: the Dijon adds a depth you’d miss if it were gone, but it doesn’t make the dish taste like mustard; the thyme gives it a woodsy note that plays against the mushroom.
- Crispy fried onions: they do double duty, about a third stirred into the beans for flavor and the rest saved for the top, where they brown and stay crunchy.
- Freshly grated Parmesan: grate it yourself if you can, since it melts more smoothly than the pre-shredded kind and browns better on top during the last twenty minutes uncovered.
How to Make Green Bean Casserole
This comes together in three stages: blanch the beans, build the sauce on the stovetop, then assemble and bake. The recipe card below carries the full step-by-step; here’s the shape of it.
Blanch and Dry the Beans
Boil the trimmed beans in well-salted water for two minutes, then move them straight to an ice bath to stop the cooking. Drain and pat them dry, because any water left on the beans thins the sauce once it all bakes together.
Build the Sauce
Soften the onion in butter, add the garlic, Dijon, and thyme, then stir in the cream of mushroom soup, heavy cream, and a few generous grinds of black pepper until it’s smooth and heated through.
Assemble and Bake
Fold the beans, sauce, about a third of the fried onions, and half the Parmesan together, spread it in the dish, and scatter the rest of the onions and Parmesan over the top. Bake covered at 350°F (177°C), then uncover to finish until it’s bubbling and the top is golden, and let it rest before serving.
You can assemble it up to a day ahead and keep it covered in the fridge; hold the topping onions until just before it goes in the oven.
Recipe Notes and Expert Tips
- Dry the beans like you mean it. Blanching leaves them wet, and wet beans are a common reason a green bean casserole turns out watery. Pat them with a towel until they stop leaving damp spots.
- Keep the blanch to two minutes and no longer. That’s enough to set the color and take the raw edge off while leaving the beans crisp-tender; another minute or two and they go limp in the oven.
- Hold most of the fried onions back until the topping goes on. Stirred in early and buried under foil, they steam soft; scattered on top for the uncovered bake, they crisp and brown.
- Taste the sauce before it meets the beans. The soup and the Parmesan both bring their own salt, so season with pepper first and add salt only if it needs it.
Recipe Variations
- Frozen green beans stand in for fresh when that’s what you have. Thaw them completely and dry them hard, or they’ll water down the sauce.
How to Store Leftovers
Get leftovers into the fridge within two hours of the casserole coming out of the oven, or within one hour if the kitchen is warmer than 90°F (32°C). Stored airtight, it keeps for three to four days. Reheat leftovers to 165°F (74°C), and scatter a few fresh fried onions over reheated portions to bring the crunch back. It freezes for up to three months, though the beans and the topping are best fresh.
Serving Suggestions
This is a holiday table side at heart, so it belongs next to the main more than in front of it. It’s at home beside a roast turkey or a baked ham, and a sweet potato casserole alongside it gives you a sweet-and-savory spread without doubling up on another creamy dish. If you’re curious how this dish became such a fixture, What your grandma’s green bean casserole still gets right is worth a read.
FAQs
Almost always because the beans went in wet. Blanch them for only two minutes and pat them thoroughly dry before they meet the sauce, and make sure the sauce itself is smooth and heated through, not thin, before you fold everything together. Water on the beans and a loose sauce are the two things that leave you with a puddle at the bottom of the dish.
Yes. Frozen green beans work well; thaw them completely and dry them well, the same as you would fresh.
You can assemble the whole casserole up to a day ahead and keep it covered in the fridge. Wait on the fried onions until just before it goes in the oven, though, or they’ll lose their crunch sitting overnight.
For fresh beans, yes. The two-minute blanch sets the color and takes the raw edge off while leaving them crisp-tender, and the ice bath stops the cooking so they hold their snap through the bake.
Green Bean Casserole
Equipment
- 11 x 7-inch baking dish
- Large pot
- Large bowl
- Small skillet
- Colander
- Large bowl for an ice bath
- Aluminum foil
Ingredients
- 2 pounds fresh green beans trimmed
- 2 tablespoons butter
- 1/4 cup finely diced white onion
- 2 cloves garlic minced
- 2 teaspoons Dijon mustard
- 1/2 teaspoon dried thyme
- 2 10.5-ounce cans condensed cream of mushroom soup
- 1/4 cup heavy cream
- 1 1/2 cups crispy fried onions divided
- 1/2 cup freshly grated Parmesan cheese divided
- Freshly ground black pepper to taste
Instructions
- Preheat the oven to 350°F and lightly coat an 11 x 7-inch baking dish with nonstick cooking spray.
- Blanch the green beans in a large pot of well-salted boiling water for 2 minutes. Immediately transfer them to an ice bath, then drain well and pat dry.2 pounds fresh green beans
- Melt the butter in a small skillet over medium heat. Add the onion and sauté until softened, about 5 minutes. Stir in the garlic and cook for 30 seconds, then add the Dijon mustard and dried thyme. Cook for another 30 seconds, stirring constantly. Stir in the cream of mushroom soup, heavy cream, and a few generous grinds of black pepper until smooth and heated through.2 tablespoons butter, 1/4 cup finely diced white onion, 2 cloves garlic, 2 teaspoons Dijon mustard, 1/2 teaspoon dried thyme, 2 10.5-ounce cans condensed cream of mushroom soup, 1/4 cup heavy cream, Freshly ground black pepper
- In a large bowl, combine the green beans, soup mixture, 1/2 cup of the crispy fried onions, and 1/4 cup of the Parmesan cheese, stirring until the beans are evenly coated.1 1/2 cups crispy fried onions, 1/2 cup freshly grated Parmesan cheese
- Transfer the mixture to the prepared baking dish and spread it into an even layer.
- Top with the remaining 1 cup of crispy fried onions and the remaining 1/4 cup of Parmesan cheese.
- Cover the casserole with aluminum foil and bake for 20 minutes.
- Uncover and continue baking for 20 minutes, or until the casserole is bubbling and the topping is golden brown.
- Let the casserole rest for 10 minutes before serving.
Video
Notes
- Dry the green beans thoroughly after blanching to keep the sauce rich and creamy.
- Frozen green beans work well, too. Thaw them completely and pat them very dry before using.
- Freshly grated Parmesan melts better and delivers more flavor than pre-shredded cheese.
- Assemble the casserole up to a day in advance, but wait to add the crispy onions until just before baking so they stay crunchy.