Slow-Cooker Green Bean Casserole

This comforting side dish takes a couple of supermarket short-cuts: Buy pre-sliced mushrooms and canned french-fried onions to save on prep time. The raw cremini mushrooms are thrown right into the slow cooker and release their savory goodness while the green beans cook.
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  • Level: Easy
  • Total: 4 hr 45 min
  • Active: 35 min
  • Yield: 8 servings
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3 pounds green beans, trimmed and cut into2-inch pieces (about 12 cups)

1 pound sliced cremini mushrooms (about 8 cups)

Kosher salt and freshly ground black pepper

4 tablespoons unsalted butter

1 large yellow onion, cut into 1/2-inch dice(about 2 cups)

2 cloves garlic, minced

1/4 cup all-purpose flour

3 cups half-and-half

2 cups canned french-fried onions


  1. Combine the green beans, mushrooms and 1 teaspoon salt in a 6-quart slow cooker.
  2. Melt the butter over medium-high heat in a large skillet. Add the onions and a pinch of salt and cook, stirring occasionally, until the onions are tender and lightly browned, 6 to 8 minutes. Reduce the heat to medium, then add the garlic and cook, stirring constantly, until the garlic is just softened, about 2 minutes. Stir in the flour and stir constantly until it thickens into a paste, about 2 minutes. Add the half-and-half and 1 teaspoon each salt and pepper and cook, whisking occasionally, until thickened, 8 to 10 minutes. Remove from the heat and season to taste with salt and pepper. Pour the sauce into the slow cooker and stir to coat the vegetables. (The sauce will loosen as it cooks.)
  3. Cover the slow cooker and cook on low until the green beans are tender but not mushy, about 4 hours. Remove the lid and stir. If the green beans look too soupy, cook for an additional 15 minutes uncovered. Season with additional salt and pepper to taste. Transfer to a shallow serving dish and sprinkle with the fried onions. Serve hot.