This homemade green bean casserole is a winner at any dinner table! With crunchy toppings and a creamy sauce, it really fills you up with flavor.
Plus, it’s super easy to make—just mix, bake, and enjoy! I love that it’s a tasty way to get my veggies in, especially when topped with those crispy onions. Yum!
Key Ingredients & Substitutions
Green Beans: Fresh green beans bring crispness and color. If they’re not available, use frozen green beans. Just thaw and add them directly to the dish without blanching!
Mushrooms: Fresh mushrooms add a wonderful depth of flavor. If you’re in a pinch, canned mushrooms are okay. I prefer using button or cremini mushrooms for their earthiness.
Cheese: Sharp cheddar gives the casserole a nice kick. You can swap it for mozzarella for a milder flavor, or even a dairy-free cheese for a plant-based option.
Fried Onions: Crunchy layers on top are essential! If you can’t find fried onions, you can use crushed crackers or breadcrumbs combined with a bit of melted butter for a crispy topping.
How Do I Achieve the Best Creamy Sauce?
The creamy sauce is the heart of this casserole! To create it successfully, follow these tips:
- Cook the flour mixture for a minute before adding the milk. This reduces the raw taste.
- Add milk slowly while whisking. This keeps lumps from forming and ensures a smooth blend.
- Cook the sauce until it thickens slightly—it should coat the back of a spoon. This tells you it’s ready!
By following these steps, your sauce will be creamy and delightful, making your casserole a hit!

Homemade Green Bean Casserole
Ingredients You’ll Need:
- 1 pound fresh green beans, trimmed and cut into 2-inch pieces
- 2 tablespoons butter
- 8 ounces mushrooms, sliced
- 3 cloves garlic, minced
- 1 small onion, finely chopped
- 1/4 cup all-purpose flour
- 1 1/2 cups whole milk
- 1 cup heavy cream
- 1 teaspoon soy sauce
- 1/2 teaspoon black pepper
- 1/2 teaspoon salt (or to taste)
- 1 cup shredded sharp cheddar cheese
- 1 1/2 cups crispy fried onions (store-bought or homemade)
How Much Time Will You Need?
This delicious green bean casserole takes about 15-20 minutes of prep time and approximately 30 minutes to bake. Including cooling, you can expect a total of about 1 hour from start to finish before you dig into this creamy, comforting dish!
Step-by-Step Instructions:
1. Preheat and Prep:
Start off by preheating your oven to 350°F (175°C). While it’s heating up, prep your green beans. Blanch the green beans in a pot of boiling salted water for around 4-5 minutes until they’re crisp-tender. Once done, drain the green beans and rinse them under cold water to halt cooking. Set them aside while you get the other ingredients ready.
2. Cooking the Flavor Base:
In a large skillet, melt the butter over medium heat. Add the chopped onion and cook until it’s softened and translucent, which should take about 3 minutes. Next, toss in the mushrooms and let them cook for 5-7 minutes until they release their moisture and start to brown. Don’t forget to add the minced garlic and cook for another minute to bring out that lovely aromatic flavor!
3. Creating the Sauce:
Now, sprinkle the flour over the mushroom mixture and stir constantly for about 1-2 minutes. This helps eliminate any raw flour taste. Then, slowly whisk in the milk and cream, mixing well to avoid any lumps. Keep cooking the sauce, stirring frequently, until it thickens and bubbles gently—this should take about 5-7 minutes. Once thickened, stir in the soy sauce, salt, and pepper. Finally, mix in 3/4 cup of the shredded cheddar cheese until it melts into a smooth sauce.
4. Combining and Assembling:
Gently fold the blanched green beans into the creamy sauce. Once everything is well combined, pour this mixture into a greased casserole dish. For the finishing touch, sprinkle the remaining cheddar cheese on top, followed by a generous layer of crispy fried onions.
5. Baking to Perfection:
Pop the casserole in the preheated oven and bake uncovered for about 25-30 minutes, or until the cheese is melted, and the top is a beautiful golden brown and bubbly. Once out of the oven, let it cool for about 5 minutes before serving!
Enjoy your delightful homemade green bean casserole, packed with flavor and perfect as a side dish or comfort food!

Can I Use Frozen Green Beans?
Absolutely! If using frozen green beans, there’s no need to blanch them. Just thaw them and add them directly to the casserole. Keep in mind that they may release a little extra moisture, so you might want to adjust the sauce’s thickness accordingly.
What Can I Substitute for Heavy Cream?
If you want a lighter version, you can substitute half-and-half or whole milk instead of heavy cream. For a dairy-free option, try coconut milk or almond milk, but be aware that this may change the flavor a bit!
How Do I Store Leftovers?
Place leftovers in an airtight container and refrigerate for up to 3-4 days. To reheat, simply warm it in the oven at 350°F (175°C) until warmed through, or use the microwave for a quicker option.
Can I Make This Casserole Ahead of Time?
Yes, you can prepare the casserole a day in advance. Assemble it without baking, cover it tightly, and store it in the fridge. When ready to serve, bake it straight from the refrigerator, adding a few extra minutes to the baking time if needed.