Green Bean Casserole from Scratch

Ditch the canned soup, and make Green Bean Casserole from scratch! Made with a creamy mushroom sauce, fresh green beans, and a homemade "fried" onion topping, this Homemade Green Bean Casserole recipe is truly the best! 

Holiday meals are not complete without this green bean casserole. And this recipe is the ONLY recipe you need when you want to prepare the BEST Green Bean Casserole.

Instead of overly processed ingredients, this recipe for green bean casserole is made completely from scratch with fresh green beans, a luscious homemade cream of mushroom soup, and a homemade crispy onion topping.

That's right. No canned soups. No canned green beans. No freeze-dried onions.

Even though this casserole swaps out the processed ingredients it is still fairly simple to make and the results are well worth the extra minimal effort.

Ingredient Swaps

• Green Beans: Instead of canned green beans, this recipe uses fresh or frozen green beans, which simply taste better. You can use either haricot verts or thicker garden green beans.
• Onion Topping: Fresh onions, flour, seasonings, and panko bread crumbs combined with a bit of oil to create a crispy oven-fried topping that is full of flavor--so much more flavor than canned fried onions.
• Homemade Cream of Mushroom Soup: This green bean casserole is made with a homemade cream of mushroom soup, instead of canned soup that is full of preservatives and high in sodium. It is thick, creamy, full of mushrooms, and actually really simple to make.

How to Make Green Bean Casserole

Step One: Prepare Onion Topping

It is best to first prepare the onion topping for the green bean casserole. That will give it time to crisp up in the oven while you prepare the green beans and sauce.

• Thinly slice an onion into ⅛-inch thick slices. You may find it easier to use a mandoline, but of course, you can use a knife as well. Once sliced, separate the onion into rings or individual strips.
• In a mixing bowl mix together oil, panko, flour, and seasoned salt. By adding the oil to the breadcrumb mixture, it will adhere to the onions without first being dipped into an egg mixture and also helps the onions to brown up beautifully.
• Toss the onions with the breading, shaking off any excess, and spread the onions out onto a sheet pan.
• Bake at 400 degrees F for 10 minutes, to just start to brown the onions. Remove from the oven and turn the heat down to 375 degrees, which is the temperature the completed casserole will bake at.

Step Two: Prepare Green Beans

When using fresh green beans in a baked casserole, they need to be blanched first. This helps the green beans to become tender and keeps their vibrant green color.

• Bring a large pot of salted water to a rapid boil.
• Trim the ends off the fresh green beans and cut them into 2-inch pieces.
• Drop the fresh (or frozen) green beans into the boiling water and cook for 5 minutes for thick green beans, and 3 minutes for thin green beans.
• Remove the beans from the boiling water with a slotted spoon and immediately place them into an ice bath to stop the cooking process.

Step Three: Prepare the Mushroom Sauce

This mushroom sauce is essentially a concentrated mushroom soup and has a similar texture to that of canned condensed soup and it is really quite simple to make.

• Over medium heat, melt butter in a heavy-bottomed skillet. Once melted, add in the mushrooms and fresh herbs if using. Saute for 3-5 minutes, until the mushrooms just begin to break down.
• Whisk in the flour, forming a roux, or thick paste, and cook for 1 minute. This will help rid the sauce of the raw flour taste.
• Whisk in the wine, or additional stock, and cook until thickened, whisking constantly.
• Slowly mix in the stock and milk, whisking to incorporate. Season with salt and pepper and cook for 2-3 minutes or until sauce is thickened and then remove from heat.

Step Four: Assemble and Bake

Now that the components are made, it is time to assemble the green bean casserole.

• Grease a 2-quart casserole dish with butter or non-stick spray.
• Drain the green beans and pat dry. Add them to the mushroom sauce and toss to coat. Spread that mixture out into the prepared pan and then top evenly with the onions.
• Bake until the mushroom sauce is bubbly and warm and the onion topping is golden brown.

Preparing in Advance

When it comes to holiday meals, it is always helpful to prepare as many dishes in advance, especially when you need your oven to cook a turkey or make Baked Ham. This green bean casserole can be made up to 24 hours in advance.

To make this casserole ahead of time, prepare the casserole as directed up to baking. Cover the baking dish with plastic wrap and refrigerate for up to 24 hours. Remove the baking dish from the refrigerator and let sit at room temperature while the oven preheats. Bake at 375 degrees F for 40-45 minutes.

Tips and Modifications

• Leftover green bean casserole can be stored in the refrigerator for 3-4 days. This casserole does not freeze well, as the cream will separate when defrosted and the onions will become soggy.
• Panko Bread Crumbs are best to keep the onions light and crispy, but traditional unseasoned bread crumbs work as well if that is all you have on hand.
• To make this Green Bean Casserole Gluten Free, Use 1:1 Gluten-Free Flour Blend and  Gluten-Free Bread Crumbs in place of the flour and panko bread crumbs.
• To make this Green Bean Casserole Dairy Free, use olive oil or non-dairy butter, such as Smart Balance in place of the butter. Instead of using milk in the mushroom sauce, I would suggest using additional stock or unflavored, unsweetened non-dairy milk (like soy, almond, or oat milk.)
• The marsala wine adds a rich depth to the casserole, but feel free to omit and use additional vegetable broth or chicken stock in its place if you don't drink wine or keep it on hand.

More Holiday-Worthy Side Dish Recipes

• Perfect Mashed Potatoes
• Homemade Cranberry Sauce
• Classic Stuffing Recipe
• Roasted Brussels Sprouts
• Corn Casserole

If you enjoyed this green bean casserole, I would love for you to leave a comment and rating below.