Slow Cooker Green Bean Casserole is a delicious combination of from-scratch cooking and slow cooker convenience. You'll want this on your menu all year round!
As much as I may identify as a "foodie" or a "lover of food," there is one thing I emphatically am not. I am not a food snob.
So when someone makes the Campbell's original green bean casserole recipe with canned green beans, canned cream of mushroom soup, and canned fried onions, I'm all over it.
And yet, the foodie in me has been wondering for quite some time... is there a better way?
Of course there is a better way! In this age of the Food Revolution, there is definitely a better way to Green Bean Casserole.
Now I know that sounds bold. It's quite an assertion to say that MY recipe is better than the version that has been beloved for 60+ years. That Campbell's recipe is practically an institution, gracing Thanksgiving tables year after year, all across the country.
But mine is made in a crock pot. On the day you use your oven the most, make this casserole in a crock pot.
But it gets better! It gets even better.
The Green Beans
Let me just get this out of the way: I am NOT recommending fresh beans here. I wish I could... I would love to... I think they would be The Ultimate.
But, here's the thing. I called my sister.
Monica is in charge of the Green Bean Casserole every Thanksgiving. If she is not willing to trim, chop, and blanch fresh green beans, then I'm not either. It just won't work. If Monica's not going to even consider my recipe, I'm not going to make it.
But canned green beans? In a crock pot? Sounds like a crock of mush.
So where does that leave us? We are left with frozen green beans. (Note: I have instructions for substituting fresh in the recipe notes for all your over-achievers out there).
And you know what? I really like the frozen green beans. You cook them in the microwave before you stir them into the sauce, and they taste great. They held their shape rather than turning to mush. And most importantly: They are convenient.
The Mushroom Sauce
We are ditching the canned cream of mushroom soup and making our own from scratch. The reason you are okay with this is because you can make it the night before.
It's also incredibly easy. Mushrooms sautéed in butter and garlic. Stir in some flour. Stir in chicken broth and cream. Simmer. Done.
The French Fried Onions
There are some traditions you just don't mess with, and the canned fried onions on green bean casserole is one of them.
With an oven-baked Green Bean Casserole, you assemble everything together and bake it. With a slow cooker, these crispy onions become a potential hazard. If you add them right away, they become softened and chewy. Not appetizing.
So, I add the crispy fried onions right at the end, right before serving. It's an easy solution with no down-side.
Green Bean Casserole For a Crowd
Reader Liz wants to make Green Bean Casserole for about 30 people, so I tripled the recipe (roughly) and tested it out. Great news! 3x-ing the recipe is a GO. See the recipe notes below for exactly what to do. At this capacity, you'll easily be able to feed 30 - 40 people as part of your general Thanksgiving feast.
WARNING: You need a large stock pot or Dutch Oven (at least 5.5 quarts) AND a large slow cooker (at least 6.5 quarts). I use this crock pot and it was filled RIGHT to the brim as you can see in the photo above.
I did not increase the amount of French Fried canned onions simply because the crock pot only has so much surface area. If you are going to serve the Green Bean Casserole on a buffet table, you may want to replenish the canned onions as the casserole is depleted. Or, transfer portions of the casserole to serving bowls and top those with the French Fried onions.
Be sure to read the recipe notes (at the end of the recipe) for my make-ahead instructions. Or if you want to use fresh green beans.
Slow Cooker Green Bean Casserole Recipe
- 3 tablespoons butter
- 1 pound white button mushrooms wiped clean, sliced or broken into pieces
- 3 cloves garlic minced
- salt and freshly ground black pepper
- 3 tablespoons all-purpose flour
- 1 1/2 cups low-sodium chicken broth
- 1 1/2 cups heavy cream
- 2 (12 ounce) packages frozen cut green beans (see notes)
- 3 cups canned fried onions
- n a large, deep skillet, saucepan, or Dutch oven, melt the butter over medium-high heat until foaming subsides. Add mushrooms, garlic, 3/4 teaspoon salt, and 1/8 teaspoon pepper.
- Cook until the mushrooms have released most of their liquid, about 5 minutes. Stir in flour and cook for one minute. Whisk in broth, scraping up any brown bits from the bottom of the pan. Bring to a boil, whisking constantly.
- Reduce heat to medium. Whisk in cream and simmer until the sauce has thickened, about 5 minutes. Season to taste with salt and pepper.
- Meanwhile, cook the beans in the microwave according to the package instructions (or microwave on HIGH power for 4 to 5 minutes; let stand 1 minute before removing from the microwave). Transfer to a colander or salad spinner and drain well. If using a salad spinner, spin out any liquid and drain.
- Add the green beans to the pot with the mushroom sauce and toss until evenly coated. Transfer the beans and sauce to a crock pot.
- Cook on HIGH for 2 hours or LOW for 4 hours or until a thermometer inserted in to the middle of the casserole reaches 165 degrees. Top with canned fried onions immediately before serving.
- For the most part, I found frozen green beans in 12-ounce packages. If you find 10-ounce packages, I would still stick to 2 packages. I have tried the recipe with 3 (10 ounce) packages and there was not enough sauce for that many beans.
- Be sure to use frozen cut green beans, not “French” green beans (the long, stringy ones) or whole, uncut beans (you’d just have extra work cutting them).
- To substitute fresh beans, start by trimming them and cutting them in half. Then, bring 4 quarts water and 1 Tablespoon salt to a boil. Meanwhile, fill a large bowl with ice and water. Cook the beans about 5 minutes, until bright green and crisp-tender. Drain the beans and immediately plunge into the ice water. Drain well before adding them to the sauce in Step 5.
- To triple the recipe for 30 to 40 people, increase the ingredients as follows: 1/2 cup (1 stick) butter 3 pounds white button mushrooms, wiped clean and sliced or broken into pieces 1 bulb garlic (9 to 10 cloves) 3 teaspoons salt and 1/2 teaspoon pepper 1 cup flour 4 1/2 cups chicken broth 4 1/2 cups heavy cream 6 (12 ounce) packages of frozen cut green beans 3 cups canned fried onions (or more if desired)
- 3x recipe instruction changes: Cook the mushrooms for about 10 minutes in Step 2 and simmer the sauce for 10 minutes in Step 3. Cook on HIGH for 2 hours or LOW for 4 hours (or until a thermometer reaches at least 165 degrees in the middle of the casserole). Add more canned onions throughout serving time if the top layer is depleted, if desired.
- The mushroom sauce may be prepared in advance, cooled, and refrigerated overnight. Increase the crock pot time to 3 hours on HIGH or 5 hours on LOW.
- If using fresh beans, they may be blanched the night before, cooled, and stirred into the cooled mushroom sauce and refrigerated overnight. Increase the crock pot time to 3 hours on HIGH or 5 hours on LOW.
- Adapted from Cook’s Illustrated Magazine, November & December 2006 issue.