Do you already have your hands full this Thanksgiving? If not, your oven probably does. Save your oven some work and let the slow cooker handle this comforting side dish. This Slow Cooker Green Bean Casserole captures all the familiar flavors of the classic Thanksgiving recipe but requires far less hands-on effort. It finishes with a crunchy, golden fried onion topping for perfect contrast.
The holiday season moves quickly here in North America: Thanksgiving rolls into cookie exchanges and then Christmas dinner. Planning helps, but using small appliances like slow cookers, Instant Pots, and air fryers can make a big difference. These helpers make feeding a crowd easier and free up oven space for the main course.
A Classic Thanksgiving Side Dish
Green bean casserole is a Thanksgiving staple and is often one of the first sides to make a holiday menu. Making it in the slow cooker lets you include this favorite without tying up the oven. Once assembled you only need to stir occasionally and add the French fried onions just before serving.
Ingredients
- Green beans: Frozen French-cut green beans are recommended because they hold up well to slow cooking and give a rustic texture. Fresh or canned beans can be used—see substitutions below.
- Cream of mushroom soup: Two cans, or about 2 2/3 cups if using a homemade version.
- Milk: A little milk thins the sauce so it coats the beans evenly.
- Shredded cheese: Optional, but adds richness and depth. Omit if you prefer the classic version without cheese.
- French fried onions: The crunchy topping makes the casserole. Toasting them briefly in an air fryer, skillet, or under the broiler improves the texture and flavor.
- Pepper: A pinch of ground black pepper to season the dish.
How to Make Green Bean Casserole in a Slow Cooker
This slow cooker version is simple and mostly hands-off. Start by combining the two cans of undiluted cream of mushroom soup in a medium bowl. Add the milk, shredded cheese (if using), and ground black pepper, then stir until smooth to create the sauce.
Place 2 pounds of green beans in the insert of your slow cooker. They can go in frozen, thawed, or lightly steamed—frozen is easiest for prep. Pour the sauce over the beans and fold gently to combine. If the beans are frozen it may be hard to distribute the sauce fully at first; stirring a few times during cooking helps.
Cook on high for 3 1/2 to 4 hours, stirring occasionally to ensure even cooking and to prevent scorching. The casserole is ready when the sauce is bubbly and the beans are tender.
How to Add Crispy French Fried Onions
Top the finished casserole with French fried onions, but toast them first for best crunch. The slow cooker’s moisture can soften raw onions, so crisping them before serving makes a big difference.
Three reliable methods to crisp the onions:
- Skillet: Melt 1 tablespoon butter over medium heat, add the onions, and toast while stirring until golden.
- Air fryer: Cook at 350°F for 1–3 minutes—quick and effective.
- Broiler: Place onions on a broiler-safe pan and broil for about 1 minute; watch carefully to avoid burning.
After toasting, scatter the onions over the casserole and serve immediately so they remain crisp. Your guests will enjoy the creamy, saucy beans with a satisfying crunchy topping.
Variations and Substitutions
With bacon: Stir 1/2 to 1 cup of cooked, crumbled bacon into the sauce for a smoky boost. Reserve extra bacon to sprinkle on top if desired.
Without cream of mushroom soup: Use a simple homemade white sauce if you prefer to avoid canned soup.
Fresh green beans: Blanch fresh beans 2–3 minutes, drain, then add to the slow cooker and follow the recipe.
Canned green beans: Substitute about four 15-ounce drained cans for the frozen beans and reduce the cooking time by 30–60 minutes.
Without cheese: Omit the cheese and prepare the dish the same way for a more traditional flavor.
No onions: If you prefer not to use French fried onions, top with buttered crushed cornflakes or crushed buttery crackers for crunch.
What Kind of Slow Cooker Is Best for Casseroles?
Most slow cookers will work, but a 6-quart or larger model is ideal for casseroles. Oval or rounded rectangular inserts are both useful; the rectangular shape often fits casserole-style recipes a bit better.
More Easy Thanksgiving Recipes:
- Instant Pot Creamed Corn
- No-Bake Pumpkin Cheesecake Bars
- Slow Cooker Maple and Brown Sugar Glazed Carrots
- Slow Cooker Funeral Potatoes
- Instant Pot 5-Ingredient Mac and Cheese
Slow Cooker Green Bean Casserole
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Ingredients
- 2 10oz cans Cream of Mushroom Soup, undiluted
- 1 cup whole milk
- 1 ½ cups shredded cheddar cheese (optional)
- ¼ teaspoon ground black pepper
- 2 lbs frozen French-style green beans
- 2 ½ cups French fried onions (about ¾ of a 6oz container or 2 x 2.8oz containers)
Instructions
- Add the two cans of undiluted cream of mushroom soup to a medium bowl.
- Add the milk, shredded cheese (if using), and ground black pepper. Fold together until thoroughly combined.
- Add 2 lbs of frozen French-style green beans to the insert of a 6-quart slow cooker.
- Pour the soup mixture over the beans and stir as best you can to distribute the sauce. Stir a few times during cooking to help thaw and coat the beans.
- Place the lid on the slow cooker and cook on high for 3 ½ to 4 hours, stirring several times to prevent scorching and ensure even cooking.
- When the casserole is bubbling and the beans are tender, prepare the French fried onions using one of these methods: skillet with butter, air fryer at 350°F for 1–3 minutes, or under the broiler for about 1 minute. Top the casserole with the toasted onions and serve immediately.
- Serve and enjoy.
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Notes
With bacon: Add ½–1 cup cooked, crumbled bacon.
Cutting in half: For a smaller crowd, halve the recipe to fit a 4-quart slow cooker.
Nutrition
| Carbohydrates: 16 g
| Protein: 10 g
| Fat: 11 g
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