Homemade Green Bean Casserole with Creamy Mushroom Sauce

My brother is a big fan of the classic version of green bean casserole served at Thanksgiving and Christmas dinner. Personally, I think it’s fine, but I’m not a huge fan. The beans are often drowning in the sauce, and I don’t like “cream of anything” from a can. I was determined to improve the recipe and find something we all could enjoy more.

This homemade dish features fresh mushrooms, a creamy sauce made from scratch, and crisp-tender green beans that still taste like real vegetables. It has all the comfort and nostalgia of the original, but with fresher flavor and a lighter texture. The sauce is easy to make. After it's baked, you still get that golden, crunchy topping everyone loves - just without the cans.

Now, it’s the version we look forward to every holiday, and even my brother admits this one has the classic beat. Not only is it perfect for a holiday feast, it also works great as a weeknight side.

Courses: Side Dishes

Ingredients

Casserole:

1-pound green beans, trimmed
1 recipe Cream of Mushroom Soup (see below)
10 oz. French-fried onions

Cream of Mushroom Soup:

2 tbsp butter
½ medium onion , minced (about 5 oz after trimming)
2 cloves of garlic, minced
6 oz. white mushrooms, sliced
1½ tbsp all-purpose flour
1 cup chicken broth; I use Better Than Bouillon made as directed.
¼ cup heavy cream
1 tsp fresh thyme leaves, minced (¼ tsp dried may be substituted, or omit)
1 tsp low-sodium soy sauce
¼ - ½ tsp garlic salt

Instructions

1
Preheat the oven to 375°F.
2
Steam the green beans for about 6 minutes, until starting to soften.
3
Pour the beans into a 9x9 casserole dish. Cover with the mushroom soup, stir, then top with a layer of fried onions.
4
Place the casserole in the oven and bake until bubbly, for 20 to 30 minutes.
5
If the onions start to brown too quickly, cover the dish loosely with foil.
6
To prepare the cream of mushroom soup:
7
Melt butter in a medium pot over medium-low heat. Add onions and cook, stirring occasionally, for about 5 - 10 minutes until softened and translucent.
8
Stir in the minced garlic and cook for 1 minute until fragrant.
9
Add sliced mushrooms and cook, stirring occasionally, for 8 to 10 minutes, until the mushrooms release their liquid and begin to turn golden brown.
10
If mushrooms aren’t browning by the 8-minute mark, increase the heat slightly.
11
Sprinkle the flour evenly over the mushrooms and stir to coat. Cook for 1 minute to remove the raw flour taste.
12
Gradually whisk in the broth, stirring constantly to avoid lumps. Bring to a simmer.
13
Lower the heat to low. Partially cover the pot and simmer for about 10 minutes. Stir occasionally until the soup thickens a bit.
14
Stir in heavy cream, thyme, and soy sauce. Simmer for 5 more minutes to combine flavors.
15
Partially blend the soup with an immersion blender. Leave some mushroom pieces for texture. If using a countertop blender, purée half the soup, then return it to the pot. Add garlic salt to finish

Note

Quick tips

Make ahead (option 1): Trim and cut beans when convenient. The mushroom soup may be made several days ahead.

Make ahead: Complete the entire recipe without adding the onions. Cover tightly and refrigerate for up to 4 days. Add the fried onions just before putting it in the oven and bake at 375°F for 30-40 minutes until bubbly. As noted above, cover loosely with foil if the onions are browning too quickly.

If the thyme is tender, use the stems and leaves. If the stems are woody, strip the leaves.

Canned cream of mushroom soup may be substituted if needed—just mix in 2 tbsp of milk, a tsp of soy sauce, and pepper to taste. Use enough to coat the beans. I much prefer the homemade version, and the limited extra effort is definitely worth it!
Holiday/Entertaining Tip:For a crowd, double the recipe and bake in a 9x13 dish. This version also holds beautifully on a buffet or keeps warm in a low oven before serving.

Quick Tips

Use buttermilk, or reduce the amount of milk slightly, for a thicker dressing. This dressing thickens a little after chilling. If it sits overnight, give it a quick stir before serving. Fresh herbs can be substituted for dried if available. Just double the amount and mince thoroughly. Use garlic powder and onion powder, NOT garlic/onion salt.

Grocery List (By Department)

Produce

1 pound of fresh green beans, trimmed
½ medium onion (about 5 oz after trimming)
2 garlic cloves
6 oz. white mushrooms, sliced
1 tsp fresh thyme leaves
Dairy
2 tbsp butter
¼ cup heavy cream
Pantry and Baking
1½ Tbsp all-purpose flour
1 tsp low-sodium soy sauce
¼ - ½ tsp garlic salt
1 cup chicken broth (or water + Better Than Bouillon, prepared as directed)

Canned and Packaged

10 oz. French-fried onions

Optional / Common Staples (check before buying)

Kosher salt and black pepper, to taste.

Olive oil or neutral cooking oil (if you like to sauté onions and mushrooms in a mix of butter and oil).