This Green Bean Casserole is a classic dish that combines tender green beans with a creamy mushroom sauce and crunchy fried onions. It’s the perfect side for family dinners!
I love how easy it is to make—just mix everything together and pop it in the oven. Plus, that crispy onion topping? It’s hard to resist sneaking an extra spoonful! 😄
Key Ingredients & Substitutions
Green Beans: Fresh green beans are best for this dish, giving the casserole a crisp texture. If fresh isn’t available, frozen green beans work too, just make sure to thaw and drain them first!
Onion: A small onion adds a nice flavor. If you’re short on time, you can use shallots or even onion powder (1 teaspoon) as a quicker alternative. I find shallots have a sweeter taste.
Mushrooms: Fresh mushrooms give a great earthy flavor. If you’re not a fan, you can substitute with canned mushrooms, but I recommend sautéing them to reduce moisture for a better texture.
Cream of Mushroom Soup: This is key for the creamy aspect. If you want a healthier option, consider making homemade cream of mushroom soup or using a different cream soup, like cream of celery, for a twist.
Whole Milk or Cream: Whole milk works perfectly, but if you’re looking for a lower-fat option, 2% milk could be used. For a richer taste, heavy cream is excellent, but might be a bit too rich for some!
What’s the Best Way to Cook Green Beans for Casserole?
Cooking the green beans properly ensures they maintain some crunch. Here’s how to do it:
- Start with a pot of salted water and bring it to a rolling boil.
- Add your trimmed and halved green beans and cook them for about 4-5 minutes. They should be tender but still vibrant.
- Drain them immediately and rinse under cold water to stop the cooking process. This also keeps their bright green color!
This method keeps the beans fresh and gives the casserole a lovely texture. Enjoy this easy recipe with your family!

How to Make Green Bean Casserole
Ingredients You’ll Need:
For the Casserole:
- 1 1/2 pounds fresh green beans, trimmed and halved
- 2 tablespoons butter
- 1 small onion, finely chopped
- 2 cloves garlic, minced
- 8 ounces mushrooms, finely chopped
- 1 can (10.5 oz) cream of mushroom soup
- 3/4 cup whole milk or cream
- 1 teaspoon soy sauce (optional)
- Salt and freshly ground black pepper, to taste
- 1 1/3 cups French fried onions, divided
- Fresh thyme for garnish (optional)
How Much Time Will You Need?
This delicious green bean casserole will take about 15 minutes to prepare, plus an additional 30-35 minutes of cooking time in the oven. Total time: around 50 minutes. It’s a simple yet satisfying dish that’s great for family dinners or holiday gatherings!
Step-by-Step Instructions:
1. Preheat the Oven:
Start by preheating your oven to 350°F (175°C). This ensures it’s ready for baking once you’re done preparing the casserole.
2. Cook the Green Beans:
In a large pot, bring salted water to a boil. Add the trimmed and halved green beans. Cook for about 4-5 minutes until they are tender-crisp. Be sure to drain them well and set them aside. This step will help in keeping the beans vibrant and crunchy!
3. Sauté the Onion and Mushrooms:
In a large skillet, melt the butter over medium heat. Add the chopped onion and cook for about 3-4 minutes until it becomes soft. Next, add the minced garlic and chopped mushrooms. Cook this mixture for about 5-7 minutes until the mushrooms release their juices and most of the liquid has evaporated.
4. Make the Sauce:
Now, stir in the cream of mushroom soup, milk (or cream), soy sauce (if using), and season with salt and pepper to taste. Mix everything well and let it cook for a few minutes until the sauce is heated through and slightly thickened. It should smell amazing!
5. Combine Everything:
Remove the skillet from heat. Gently fold the cooked green beans and about 2/3 cup of the French fried onions into the sauce. Make sure everything is well coated.
6. Transfer to Baking Dish:
Pour the green bean mixture into a greased baking dish. Spread it out evenly to ensure it cooks nicely.
7. Bake the Casserole:
Place the baking dish in the oven and bake uncovered for about 25 minutes.
8. Add the Fried Onions:
After 25 minutes, take the casserole out and sprinkle the remaining French fried onions evenly over the top. This will give it that delightful crunch!
9. Final Bake:
Return the casserole to the oven and bake for an additional 5-10 minutes, or until the onions are golden brown and crispy. Keep an eye on them so they don’t burn!
10. Serve and Enjoy:
If you’d like, garnish with fresh thyme for a lovely presentation. Serve warm and enjoy this comfort dish with your family and friends!
Can I Use Frozen Green Beans Instead?
Yes, you can! Just make sure to thaw and drain them completely before adding them to the casserole. This helps prevent excess moisture that could make the casserole soggy.
How Can I Make It Vegetarian?
This recipe is already vegetarian-friendly as it uses cream of mushroom soup. If you want to make sure it’s vegan, opt for a plant-based cream soup and substitute the butter with a vegan alternative. You can also use non-dairy milk!
What If I Don’t Have Cream of Mushroom Soup?
No worries! You can make a homemade version by sautéing mushrooms and onions, then mixing them with a roux (butter and flour) and vegetable broth. This homemade alternative will also enhance the flavor!
How Should I Store Leftovers?
Store leftover casserole in an airtight container in the fridge for up to 3 days. You can reheat it in the oven at 350°F (175°C) until warmed through or in the microwave, covering it to keep moisture in.



