Easy Homemade Green Bean Casserole With Frozen Green Beans

Looking to elevate your classic green beans to an incredibly delicious level? This recipe for green bean casserole is exactly what you need. Made with frozen green beans, homemade cream of mushrooms, and topped with crunchy fried onions, this amazingly flavorful casserole is not only the perfect side dish for your Thanksgiving dinner but can also be enjoyed all year round!
Green Bean Casserole pinit

About This Healthy Green Bean Casserole Recipe

The green bean casserole is a classic Thanksgiving side dish that has been around since the mid-century. It originated at a time when recipes were full of canned and processed foods. Now, more than 50 years later, I’m glad that cooking fresh and from scratch is again the preferred choice. It is not only healthier but also makes any meal incomparably more delicious.

My version of this recipe includes mushrooms sautéed with onion and garlic, which take this classic dish to the next level with incredible flavor. My favorite part about this casserole? That crunchy, flavorful onion added on top!

I did not grow up with this side dish, and when I first tried it, I used canned cream of mushrooms soup and canned green beans. I must admit that the flavor was not great; it was pretty tasteless, and the texture was not my favorite either — too mushy for my taste. Overall, it was an unappealing experience.

But I love green beans, so, of course, I needed to try and make a better and more flavorful version.

This recipe stands out because it is made with a rich homemade cream of mushrooms and frozen green beans that keep their freshness, texture, and flavor exactly as the fresh ones.

If you’re not a fan of mushy and insipid green beans casserole, try this recipe! It’s really surprising how much of a difference using fresh ingredients can make to a dish!

Green Bean Casserole

What You Need for This Green Bean Casserole Recipe

Green Bean Casserole Recipe Ingredients

Ingredient Notes

  • Green Beans: I have used frozen green beans that are perfect for this recipe because they retain the freshness, texture, and flavor of fresh beans.
  • Mushrooms: I like to use brown cremini mushrooms because they are firmer than the common white button mushroom.
  • Onion & Garlic: Fresh onion and garlic give the mushroom cream a wonderful flavor.
  • Butter: I have used unsalted butter.
  • Parmesan Cheese: Just a little bit of freshly grated parmesan cheese makes the mushroom cream so rich.
  • Flour: I have used plain/all-purpose flour to help thicken the mushroom sauce.
  • Milk & Heavy Cream: I have used full-fat milk and cream to give richness to the sauce.
  • Thyme: It adds a subtle earthy flavor with floral hints — a little bit sweet and peppery.
  • Fried Onions: To add that touch of crunchiness to the casserole.

Green Bean Casserole

Ingredient Substitutions

  • Green Beans: I have used frozen green beans, but you can also use fresh green beans. If you use them fresh, you need to blanch them first.
  • Milk: I have used it to add a lovely richness to the sauce. But can be substituted with vegetable broth.
  • Cremini Mushrooms: Can be substituted with Portobello mushrooms, which are the same variety, just a stage older, and are meatier and more flavorful.
  • Thyme: I like to use fresh thyme, but it may be substituted with dried thyme or a mix of herbs.

Green Bean Casserole


Can I make the green bean casserole in advance?

Yes! You can make this casserole 24-48 hours in advance and keep it covered in the refrigerator. Make sure you add the fried onions just before cooking.

Can I use canned green beans?

Canned green beans tend to be mushy and tasteless once cooked in the casserole, but frozen or fresh beans remain perfectly crunchy and full of flavor. Once you use it, I promise you will never go back to the can again.

Can this green bean casserole be frozen?

I wouldn’t suggest freezing this green bean casserole. Sauces thickened with flour do not freeze and/or thaw well.

Easy Homemade Green Bean Casserole With Frozen Green Beans

Difficulty: Beginner Prep Time 15 min Cook Time 25 min Total Time 40 mins


This green bean casserole made with creamy homemade mushroom sauce and topped with crunchy fried onions is the perfect side to make any dinner special!

Yield: 2 servings, baking dish size 20x14x5cm (8x6x2inches)


How To Make Green Bean Casserole From Scratch

  1. Preheat the oven to 180℃ (350℉). Clean the mushrooms and then slice them.

    Green Bean Casserole Recipe Step 1
  2. Heat a large skillet over medium heat, then add the extra virgin olive oil. Shake to coat the surface of the pan, then add the mushrooms, chopped garlic, and onion, and season with salt and pepper.

    Sauté the mushrooms for 5-7 minutes or until they release all their moisture, and the edges of the mushrooms begin to brown slightly.

    Green Bean Casserole Recipe Step 2
  3. Add the butter and flour into the same pan with the mushrooms. Keep stirring for 2-3 minutes, or just until the flour begins to coat the bottom of the pan and turn golden brown.

    Green Bean Casserole Recipe Step 3
  4. Whisk the milk and cream into the pan until all the flour from the bottom of the pan has melted. Let the sauce come to a boil as you whisk, and continue to simmer until it thickens, about 2-3 minutes. Taste the sauce and add, if necessary, another pinch of salt and pepper.

    Green Bean Casserole Recipe Step 4
  5. Remove the pan from the heat and add half of the freshly grated parmesan cheese, the green beans, and the thyme leaves.

    Green Bean Casserole Recipe Step 5
  6. Transfer the beans and sauce to a baking dish and sprinkle the remaining grated parmesan cheese on top.

    Green Bean Casserole Recipe Step 6
  7. Cook the green bean casserole for 20-25 minutes, or until it is lightly browned on top and around the edges. Top with the fried onions, and continue to bake until onions are slightly darker and fragrant, about 5 minutes. Serve hot.

    Green Bean Casserole Recipe Step 7


  • Don’t let the mushroom sauce get too thick because it will thicken up more in the oven.