Why wait for the holidays to enjoy homemade green bean casserole? This recipe includes a delicious, made-from-scratch sauce with bacon and shallots over frozen green beans that cook to perfection in the slow cooker.

Slow Cooker Green Bean Casserole on black plate and fork served

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If there ever was a holiday made for the slow cooker – it’s Thanksgiving! Besides the turkey, it’s a given you’ll find a heaping scoop of green bean casserole on my plate! This recipe is easy enough to prepare with a full menu during the holidays or just a weeknight gathering.

What’s To Love About This Recipe

Many of us love to serve green bean casserole with our holiday favorites, but it can be tricky to time everything just right! The slow cooker lets you prepare some dishes earlier than others and you can “set it and forget it.” Your mental energy – and your oven! – will be freed up to focus on other dishes.
Using the slow cooker for green bean casserole with frozen beans ensures even cooking all the way through. It also prevents overcooked or burnt edges that can happen in the oven.
With the slow cooker on your counter, you will use less energy than heating the oven for several hours. When you have lots to cook, this can really reduce your oven time!
Another bonus of the slow cooker is that it requires less monitoring. This is the perfect solution for busy days or when you have multiple dishes to prepare.
Lastly, my easy slow cooker green bean casserole utilizes a homemade sauce which is healthier than canned soups full of preservatives or nonessential ingredients. And, it’s super simple to make!

Ingredients Needed

Green beans – For this slow cooker recipe, we’re going to get super specific with our green beans! Use frozen extra-fine green beans for the best flavor and texture. These will cook well in the slow cooker and still have a little crunch!
Bacon – Use thick-cut bacon for delicious bites of flavor. Chop it up finely to distribute it throughout the casserole.
Shallot – Mince a shallot to add a slight sweetness to the green beans.
Minced garlic – I used jarred minced garlic for convenience, but you could also finely mince fresh garlic cloves.
Flour – Thicken the sauce with a bit of all-purpose flour. Gluten-free all-purpose flour also works as a substitute!
Chicken broth – Use your preferred chicken broth or bone broth.
Heavy cream – Don’t skimp on full-fat heavy cream! It replaces typical “cream of” soups and provides the richness necessary for a thick, creamy sauce.
Seasonings – Season the sauce with salt and homemade herb and garlic seasoning (or a store-bought version of the seasoning blend).
Parmesan cheese – Fresh parmesan (versus grated) yields the best results since it melts better into the sauce. However, you can also omit the cheese if you prefer.
French fried onions – Use classic crispy onions to top off the casserole. Nowadays, you can usually find a gluten-free version from several different brands as well!

Ingredients, frozen extra fine green beans, slices thick cut bacon chopped finely, 1 medium shallot minced (about 1/4 cup), 2 cloves minced garlic I used jarred 1/4 cup flour, 2 1/2 cups chicken broth, 1 cup heavy cream 1/2 teaspoon salt, 1/4 teaspoon herb and garlic seasoning, 1 cup Parmesan cheese, 6 oz french fried onions laid out on the counter

How To Make Green Bean Casserole In The Slow Cooker

Spray slow cooker with nonstick cooking spray.
Add frozen green beans to the slow cooker.

In a skillet over medium-high heat, sauté bacon until lightly browned (around 3-5 minutes).
Add shallots and sauté for another 1-2 minutes until they just start to brown.
Add minced garlic and cook for 1 more minute.

Chopped up bacon and shallow in skillet coaching in oil

Finely chopped bacon, shallot, and garlic in a skillet cooking in oil

Add flour evenly to the pan, and stir the sauce to coat the bacon, shallots, and garlic.
Slowly add chicken broth while stirring until smooth.
Let the mixture simmer for about 4-6 minutes until the sauce thickens enough to stick to a spoon.
Add cream and seasonings and let the mixture continue to simmer for another 3-4 minutes until it is thick and heated through.

Finely chopped bacon, shallot, salt, and garlic in a skillet cooking in oil

Finely chopped bacon, shallot, salt, garlic, and chicken broth in a skillet cooking in oil

Pour sauce over the green beans in the slow cooker and toss lightly to evenly coat them.
Sprinkle the green beans with cheese, cover, and cook on high for 2 ½ to 3 hours or low for 5 to 6 hours.

Slow Cooker Green Bean Casserole in ceream in slow cooker

About 15 minutes before serving, sprinkle French-fried onions across the top and let the casserole heat on high until lightly crispy.

Slow Cooker Green Bean Casserole cooking in slow cooker and 6 oz french fried onions laid on top

Recipe Substitutions and Variations

I recommend sticking to the thin, frozen green bean variety, although you can use fresh green beans instead if you prefer. Factor this into your cooking time since it will take a bit longer for the green beans to soften. If you need them to cook faster, try parboiling them before adding them to the slow cooker.
I left mushrooms out this time to make it a more universally appealing dish, but you can add some if you like! Slice them and add them to the sauce along with the garlic and shallot.
Feel free to swap out parmesan cheese for another favorite shredded cheese like cheddar or Colby jack.
If you like a bit of spice, add just a sprinkle of crushed red pepper to the sauce.
For a gluten-free version, use gluten-free flour and gluten-free French fried onions.

What To Serve With Green Bean Casserole

Most of us probably save this yummy casserole for our Thanksgiving holiday plates, so it’s only natural to serve it with some extra sides! Of course, you have to include some scrumptious carbs like Creamy Garlic Mashed Potatoes or Slow Cooker Cheesy Potatoes.

In my opinion, this casserole also deserves more time on regular menus! Try serving it with your main protein for a family dinner at home. Slow Cooker Roast Beef with Rosemary and Garlic would be a perfect choice for a delicious meal any time of the year.

Slow Cooker Green Bean Casserole served on plate

Storing and Reheating

Store leftover casserole in an airtight container in the fridge for up to 3-4 days. To reheat, try these tips for the best results:

Microwave: Heat in a microwave-safe dish, stirring occasionally.
Oven: Reheat in a preheated oven at 350°F for about 15-20 minutes.

This dish doesn’t freeze well due to the cream-based sauce and is best eaten within a few days of refrigeration.