Ingredients:

  • 5 cups thinly sliced shallots (about 6 medium)
  • 1/4 cup all-purpose (plain) flour (for coating shallots)
  • 3 cups neutral cooking oil (e.g., Canola or Vegetable), for frying
  • Fine sea salt, to taste
  • 2 lbs fresh green beans (Haricot Verts preferred), trimmed and cut into 1-inch pieces
  • 1 tbsp fine sea salt (for blanching water)
  • 4 tbsp unsalted butter
  • 10 oz sliced Cremini (Chestnut) mushrooms
  • 2 cloves minced garlic
  • 1/4 cup Dry Sherry or Madeira Wine (optional)
  • 1/4 cup all-purpose (plain) flour (for the roux)
  • 1 cup warm chicken or vegetable stock (low sodium)
  • 5 cups warm whole milk
  • 1/2 cup heavy cream (double cream)
  • 1 tsp Worcestershire sauce
  • 1/2 tsp freshly ground black pepper
  • 1 tsp finely chopped fresh thyme leaves
  • Pinch freshly grated nutmeg

Instructions:

  1. Prepare the Green Beans: Bring a large pot of salted water to a rolling boil. Drop the trimmed green beans into the water and blanch for 3–4 minutes until bright green and tender-crisp. Immediately plunge the beans into an ice bath to stop the cooking. Drain thoroughly and set aside.
  2. Fry the Shallots: Toss the thinly sliced shallots with 1/4 cup of flour until lightly coated. Heat the oil in a Dutch oven or deep skillet to 325°F (160°C). Fry the shallots in batches, stirring occasionally, until deeply golden brown and crisp (5–7 minutes per batch).
  3. Drain and Season Shallots: Remove the fried shallots with a spider and transfer them immediately to a wire rack lined with paper towels. Season generously with fine salt while still hot. Reserve the frying oil.
  4. Sauté Mushrooms: Melt 2 tbsp (28g) of butter in the large skillet over medium-high heat. Add the sliced mushrooms and sauté until all moisture has evaporated and they are richly browned and caramelized (8–10 minutes). Add the minced garlic and thyme, cooking for 1 minute.
  5. Deglaze (Optional): If using, pour in the sherry/Madeira and scrape up any browned bits from the bottom of the pan. Cook until the liquid is almost completely reduced. Remove the mushrooms and set aside.
  6. Make the Roux: Return the pan to medium heat and add the remaining 2 tbsp (28g) of butter. Once melted, whisk in the 1/4 cup of flour and cook, stirring constantly, for 1–2 minutes until a pale roux forms.
  7. Build the Sauce: Slowly whisk in the warm stock until smooth. Then, gradually whisk in the warm milk and heavy cream. Bring the sauce to a gentle simmer, whisking constantly, until thickened sufficiently to coat the back of a spoon (4–5 minutes).
  8. Season the Sauce: Remove the pan from the heat. Stir in the Worcestershire sauce, black pepper, nutmeg, and a generous pinch of salt. Fold in the reserved sautéed mushrooms.
  9. Combine Components: Preheat oven to 375°F (190°C). Gently fold the blanched, drained green beans into the mushroom cream sauce. Check the seasoning one final time.
  10. Assemble Casserole: Transfer the mixture to the prepared 9x13 inch casserole dish.
  11. Bake: Bake for 20–25 minutes, or until the sauce is bubbly and the edges are lightly browned.
  12. Garnish and Serve: Remove the casserole from the oven. Let it rest for 5 minutes. Just before serving, scatter the crispy fried shallots evenly over the top. Serve immediately.