Slow-Cooker Green Bean Casserole with Crispy Onions


Thanks to fresh green beans, an easy homemade cream sauce and crispy onion topping, this green bean casserole recipe is healthier and more delicious than traditional recipes that use canned soup, beans and onions. Plus, the slow cooker saves you time cooking at the stove. Make sure to use fresh green beans, as frozen green beans will become mushy.

Prep Time:
40 mins
Additional Time:
2 hrs 20 mins
Total Time:
3 hrs
12 servings


Green Beans & Mushrooms

  • 2 ½ pounds fresh green beans, trimmed and cut into thirds

  • 1 (10 ounce) package mushrooms, sliced

  • 1 large onion, chopped

  • 3 large cloves garlic, minced

  • 3 tablespoons extra-virgin olive oil

  • 1 ¼ teaspoons salt

  • ½ teaspoon ground pepper

Onion Topping

  • 1 medium onion, halved and sliced

  • 1 cup buttermilk

  • cup all-purpose flour

  • ¼ teaspoon ground pepper

  • teaspoon salt

  • Canola or olive oil cooking spray


  • 3 tablespoons cornstarch

  • 2 tablespoons dry sherry

  • 1 cup sour cream, at room temperature

  • ½ teaspoon dried thyme


  1. To prepare green beans & mushrooms: Combine green beans, mushrooms, chopped onion, garlic, oil, 1 1/4 teaspoons salt and 1/2 teaspoon pepper in a 5 1/2- to 6-quart slow cooker. Cook on High until tender, about 2 1/2 hours.

  2. Meanwhile, preheat oven to 400 degrees F.

  3. To prepare onion topping: Combine sliced onion and buttermilk in a medium bowl. Let stand for 15 minutes. Drain (discard buttermilk) and return the onion to the bowl. Sprinkle with flour, pepper and salt and toss to coat well. Transfer to a large rimmed baking sheet. Generously coat with cooking spray. Bake, stirring once or twice, until tender and crisp, 25 to 28 minutes. Let stand at room temperature for up to 2 hours.

  4. To prepare sauce: When the vegetables are done, combine cornstarch and sherry in medium bowl; stir until smooth. Add sour cream and stir to combine well. Add the sour cream mixture and thyme to the vegetables; stir until well coated with the mixture. Cover and continue cooking for 20 more minutes. Serve topped with the crispy onions.


Equipment: 5 1/2- to 6-quart slow cooker

Nutrition Facts (per serving)

133 Calories
7g Fat
15g Carbs
4g Protein
Nutrition Facts
Servings Per Recipe 12
Calories 133
% Daily Value *
Total Carbohydrate 15g 6%
Dietary Fiber 3g 11%
Total Sugars 5g
Protein 4g 7%
Total Fat 7g 9%
Saturated Fat 2g 11%
Cholesterol 10mg 3%
Vitamin A 728IU 15%
Vitamin C 14mg 15%
Folate 52mcg 13%
Sodium 273mg 12%
Calcium 67mg 5%
Iron 1mg 7%
Magnesium 31mg 7%
Potassium 372mg 8%

Nutrition information is calculated by a registered dietitian using an ingredient database but should be considered an estimate.

* Daily Values (DVs) are the recommended amounts of nutrients to consume each day. Percent Daily Value (%DV) found on nutrition labels tells you how much a serving of a particular food or recipe contributes to each of those total recommended amounts. Per the Food and Drug Administration (FDA), the daily value is based on a standard 2,000 calorie diet. Depending on your calorie needs or if you have a health condition, you may need more or less of particular nutrients. (For example, it’s recommended that people following a heart-healthy diet eat less sodium on a daily basis compared to those following a standard diet.)

(-) Information is not currently available for this nutrient. If you are following a special diet for medical reasons, be sure to consult with your primary care provider or a registered dietitian to better understand your personal nutrition needs.

Related Articles