📝 About This Recipe
This isn't your average holiday side dish; it’s a sophisticated reimagining of an American classic that replaces canned shortcuts with fresh, soulful ingredients. We swap the traditional cream of mushroom soup for a velvety, scratch-made sauce of sautéed cremini and shiitake mushrooms, finished with a touch of heavy cream and fresh thyme. Topped with hand-battered crispy shallots, this casserole offers a perfect harmony of tender-crisp garden beans and umami-rich decadence that will redefine your holiday table.
🥗 Ingredients
The Vegetables
- 2 pounds Fresh Green Beans (trimmed and halved if very long)
- 2 tablespoons Kosher Salt (for blanching water)
The Mushroom Sauce
- 4 tablespoons Unsalted Butter (divided)
- 10 ounces Cremini Mushrooms (thinly sliced)
- 4 ounces Shiitake Mushrooms (stems removed, sliced)
- 3 cloves Garlic (minced)
- 1/4 cup All-Purpose Flour
- 1 1/2 cups Chicken or Vegetable Stock (low sodium)
- 1 cup Heavy Cream
- 1 teaspoon Fresh Thyme (leaves stripped from stem)
- 1/8 teaspoon Ground Nutmeg (freshly grated is best)
- to taste Salt and Black Pepper
The Crispy Topping
- 3 pieces Large Shallots (peeled and sliced into thin rings)
- 1/2 cup All-Purpose Flour (for dredging)
- 1/2 cup Panko Breadcrumbs
- 1/2 cup Neutral Oil (for shallow frying)
👨🍳 Instructions
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1
Preheat your oven to 375°F (190°C) and lightly grease a 9x13 inch baking dish with butter.
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2
Bring a large pot of salted water to a rolling boil. Prepare a large bowl of ice water nearby.
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3
Blanch the green beans in the boiling water for 3-5 minutes until they are bright green and just tender-crisp. Immediately plunge them into the ice water to stop the cooking process.
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4
Drain the cooled beans and pat them thoroughly dry with a clean kitchen towel. Moisture is the enemy of a good casserole! Set aside.
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5
In a large skillet over medium-high heat, melt 2 tablespoons of butter. Add the sliced mushrooms and cook undisturbed for 3 minutes to develop a deep brown sear.
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6
Stir the mushrooms and continue cooking until their moisture has evaporated. Add the minced garlic and cook for 1 minute until fragrant.
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7
Lower the heat to medium and add the remaining 2 tablespoons of butter. Once melted, sprinkle in 1/4 cup of flour. Whisk constantly for 2 minutes to cook out the raw flour taste.
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8
Slowly pour in the stock while whisking vigorously to avoid lumps. Gradually add the heavy cream, thyme, and nutmeg.
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9
Simmer the sauce for 5-8 minutes until it thickens enough to coat the back of a spoon. Season generously with salt and pepper.
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10
While the sauce simmers, toss the shallot rings in 1/2 cup flour. Heat oil in a small pan and fry the shallots in batches until golden brown. Drain on paper towels and toss with Panko and a pinch of salt.
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11
Combine the blanched green beans and the mushroom sauce in the prepared baking dish, stirring gently to ensure every bean is coated.
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12
Bake the casserole uncovered for 20 minutes until the sauce is bubbling around the edges.
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13
Remove from the oven and sprinkle the crispy shallot and Panko mixture evenly over the top.
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14
Return to the oven for an additional 5-10 minutes until the topping is deeply golden and shatteringly crisp.
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15
Let the casserole rest for 5 minutes before serving to allow the sauce to set slightly.
💡 Chef's Tips
Always use fresh green beans; frozen or canned beans will become mushy in the homemade sauce. Don't skip the ice bath! It preserves the vibrant green color and ensures the beans don't overcook in the oven. If the sauce seems too thick, whisk in an extra splash of stock before adding the beans. For a flavor boost, add a teaspoon of soy sauce or Worcestershire sauce to the mushroom mixture for extra umami depth. Make ahead: You can prepare the beans and sauce a day in advance, store them separately, and combine/bake when ready.
🍽️ Serving Suggestions
Serve alongside a classic Roasted Turkey with Sage Stuffing for a traditional holiday feast. Pairs beautifully with a crisp Chardonnay or a light-bodied Pinot Noir. Excellent as a side to Garlic Herb Crusted Prime Rib. Accompany with a bright cranberry orange relish to cut through the richness of the cream sauce. Serve with buttery mashed potatoes to soak up any extra mushroom velouté.