Homemade Creamy Green Bean Casserole

Growing up, green bean casserole always meant the version with canned soup and those crispy onions from a container. It showed up, did its job, and nobody really asked questions.

But this is what happened when I started wondering if we could keep the part everyone likes and make the rest a little better! So I used fresh green beans, made the mushroom sauce from scratch, and gave the onions their own little crispy side quest.

The result is creamy without turning mushy, and the green beans still taste like green beans. A surprisingly important detail.

And those onions on top? They stay crisp enough that I usually start stealing a few before the dish reaches the table. This is apparently part of the process now haha.

Homemade Green Bean Casserole

This Homemade Green Bean Casserole uses fresh green beans, a creamy mushroom sauce made from scratch, and oven-baked crispy onions instead of canned soup and packaged fried onions. Some of those onions get folded into the casserole, while the rest stay on top where they can remain gloriously crunchy!

Print Recipe

PREP: 30 minutes mins

COOK: 40 minutes mins

TOTAL: 1 hour hr 10 minutes mins

Servings: 6

Course: Side Dish

Ingredients

  

For the green beans

• 10.6 ounces fresh green beans
• Salt as needed

For the creamy mushroom sauce

• 0.7 ounce unsalted butter about 1 tablespoon + 1¼ teaspoons
• 5.3 ounces button mushrooms sliced
• 1 garlic clove finely minced
• 0.6 ounce all-purpose flour about 2 tablespoons + 1 teaspoon
• 4.4 ounces vegetable or chicken broth by weight about ½ cup + 1½ teaspoons
• 2.6 ounces whole milk by weight about ¼ cup + 1 tablespoon
• 2.6 ounces heavy cream by weight about ¼ cup + 1 tablespoon
• Salt as needed
• Ground black pepper as needed

For the crispy onions

• 2 medium yellow onions
• 1.4 ounces all-purpose flour about ⅓ cup
• 1 large egg
• 0.35 ounce milk about 2 teaspoons
• 1.1 ounces panko breadcrumbs
• Salt as needed
• Ground black pepper as needed
• Cooking spray or a little vegetable oil

Instructions

 

1. Preheat the oven to 375°F and line a baking sheet with parchment paper.
2. Peel the onions and slice them very thinly. Gently separate the rings, trying to keep as many intact as possible.
3. Set up three shallow bowls. Put the flour in the first. Whisk the egg and milk together in the second. Add the panko to the third and season it lightly with salt and black pepper.
4. Coat each onion ring in the flour and shake off the excess. Dip it into the egg mixture, then coat it well with panko.
5. Arrange the breaded onions on the prepared baking sheet in a single layer without overlapping. Lightly spray them with cooking spray or drizzle very lightly with oil.
6. Bake for about 15 minutes, turning them partway through, until golden and crisp. Keep a close eye on the thinner pieces near the end because they can brown quickly. Set aside.
7. Reduce the oven temperature to 350°F.
8. Trim the green beans. Bring a large pot of lightly salted water to a boil, then cook the beans for about 8–10 minutes, until tender but still firm.
9. Transfer the beans immediately to a bowl of ice water to stop the cooking. After a few minutes, drain them again and dry them VERY well with a clean kitchen towel or paper towels.
10. Melt the butter in a large skillet over medium heat. Add the garlic and cook for about 30 seconds.
11. Add the sliced mushrooms and cook for about 8 minutes, stirring occasionally, until they release most of their moisture and begin to brown.
12. Sprinkle the flour over the mushrooms and stir well. Cook for about 1 minute so the flour absorbs the cooking juices.
13. Gradually pour in the broth while stirring continuously until the mixture is smooth.
14. Add the milk and heavy cream. Reduce the heat slightly and cook for a few minutes, stirring often, until the sauce starts to thicken. It should be creamy but still a little loose because it will continue thickening in the oven.
15. Season with salt and black pepper as needed.
16. Add the well-dried green beans to the mushroom sauce and gently stir until evenly coated.
17. Roughly crumble about one-third of the crispy onions and fold them into the green bean mixture.
18. Transfer everything to a baking dish and spread it out evenly.
19. Bake at 350°F for about 15 minutes, until the sauce is hot and gently bubbling around the edges.
20. Remove the casserole from the oven and scatter the remaining crispy onions over the top.
21. Return it to the oven for another 5 minutes, just long enough to warm the onions without sacrificing all that crunch we worked unnecessarily hard to protect haha.
22. Let the casserole rest for about 5 minutes before serving.

Notes

• Dry the beans really well. Water clinging to them can thin out the mushroom sauce.
• Watch the onions closely. Thin onion rings can go from golden to very enthusiastic in the last few minutes.
• Keep the sauce a little loose. It will thicken more once the casserole goes into the oven.
• Using frozen green beans? Cook them for about 1–2 minutes less than the package directions before adding them to the casserole.

Did you make this? Leave a rating below!

There are a few parts here, but none of them are difficult! The trick is just doing them in the right order so the onions stay crisp and the sauce stays creamy.

Gather all of your ingredients.

Slice the onions. Let’s start by peeling the onions and slicing them very thinly, then gently separate the rings. Try to keep as many intact as you can, but nobody is grading the circles.

Set up the breading station. Put the flour in one shallow bowl. Whisk the egg and milk together in another, then add the panko to a third bowl with a little salt and black pepper.

Bread the onions. Coat each onion ring in flour and shake off the excess. Dip it into the egg mixture, then press it into the panko until nicely coated.

Bake the onions. Arrange them in a single layer on a parchment-lined baking sheet and lightly spray with oil. Bake at 375°F for about 15 minutes, turning them partway through. Keep an eye on the thinner pieces near the end because they can go from golden to deeply committed very quickly.

Prep the green beans. Trim the ends and then cook the beans in lightly salted boiling water for about 8–10 minutes. They should be tender but still firm.

Cool them quickly. Transfer the beans straight into a bowl of ice water to stop the cooking. Let them sit for a few minutes and then drain them really well.

Start the mushroom sauce. Melt the butter in a large skillet over medium heat, then add the garlic. Cook it for about 30 seconds.

Cook the mushrooms. Add the sliced mushrooms and cook for about 8 minutes, stirring now and then, until they’ve released most of their moisture and started to brown.

Add the flour. Sprinkle it over the mushrooms and stir well. Let it cook for about 1 minute so it absorbs the juices in the pan.

Pour in the broth. Add it gradually while stirring so the sauce stays smooth and lump-free.

Finish the sauce. Add the milk and heavy cream, then lower the heat slightly. Cook for a few minutes until the sauce starts to thicken. You want it creamy but still a little loose because the oven has more work to do.

Season it. Add salt and black pepper to taste.

Add the green beans. Stir the well-dried beans into the mushroom sauce until everything is evenly coated.

Fold in some crispy onions. Roughly crumble about one-third of the baked onions and gently mix them into the casserole. This is where the onions begin their second career.

Fill the baking dish. Transfer the green bean mixture to the baking dish and spread it out evenly.

Bake the casserole. Lower the oven to 350°F and bake for about 15 minutes, until the sauce is hot and gently bubbling around the edges.

Add the rest of the onions. Scatter the remaining crispy onions over the top and then return the dish to the oven for another 5 minutes. Just enough time to warm them without undoing all that crispiness we worked for.

Let it rest. Give the casserole about 5 minutes before serving, just to let the sauce settle a little.

Storage and Make-Ahead

Make ahead: You can cook the green beans and make the mushroom sauce earlier in the day, then refrigerate them separately or assemble the casserole without the crispy onions. Make the onions closer to baking time, then fold in some and save the rest for the top.

Store leftovers: Keep leftovers covered in the refrigerator for up to 3–4 days.

Reheat: For a larger portion, cover the casserole loosely with foil and warm it in a 350°F oven until heated through. If the sauce looks a little thick after chilling, a small splash of milk or broth can help loosen it. Individual portions can go in the microwave, though the onions will soften a bit.

Freeze: For the best texture, freeze the green bean and mushroom mixture without the crispy onions. Let it cool completely, wrap it well, and freeze for up to about 2 weeks. Reheat it covered at 350°F until hot, then add the crispy onions near the end so they keep their crunch.

More Thanksgiving Recipes

If you’re planning Thanksgiving dinner, this green bean casserole already has the vegetable situation handled. Now you can add creamy baked mac and cheese, sausage apple stuffing muffins, or sweet potato casserole with marshmallows and suddenly the side of the plate is getting very crowded. A nice problem to have haha.