Ingredients:

  • 4 large shallots (or 2 medium yellow onions), thinly sliced
  • 3 Tbsp all-purpose flour (for coating shallots)
  • 3 cups neutral oil (for frying)
  • Fine sea salt, to taste
  • 4 Tbsp unsalted butter
  • 1/2 medium yellow onion, finely diced
  • 10 oz cremini mushrooms, sliced thinly
  • 2 cloves garlic, minced
  • 1 tsp fresh thyme leaves
  • 1 Tbsp sherry or dry white wine (optional)
  • 1/4 cup all-purpose flour (for roux)
  • 1 cup low sodium chicken or vegetable stock, warmed
  • 1 1/2 cups whole milk or half-and-half, warmed
  • Kosher salt and freshly ground black pepper, to taste
  • 2 lbs fresh green beans, ends trimmed

Instructions:

  1. Blanch the Beans: Bring a large pot of salted water to a rapid boil. Add the trimmed green beans and cook for 4–5 minutes until tender-crisp (al dente) and bright green.
  2. Shock the Beans: Immediately plunge the beans into a large bowl of ice water to halt cooking and set the colour. Drain thoroughly and set aside.
  3. Prepare Shallots for Frying: Toss the thinly sliced shallots with the 3 Tbsp of flour and a pinch of salt. Ensure they are evenly coated.
  4. Fry the Shallots: Heat the 3 cups (700 mL) of neutral oil in the heavy-bottomed pot to 325°F (160°C). Fry the shallots in batches, stirring constantly, until deeply golden brown (about 3–5 minutes per batch).
  5. Drain and Season: Use a spider to remove the shallots and immediately spread them in a single layer on the wire rack lined with paper towels. Season immediately with a final pinch of salt. Set aside.
  6. Sauté Aromatics: Melt the butter in the sauté pan over medium heat. Add the diced onion and sauté until softened (3–4 minutes). Add the sliced mushrooms and a pinch of salt. Cook until the mushrooms have released their liquid and are browned and caramelised (8–10 minutes).
  7. Add Garlic and Wine: Stir in the minced garlic and thyme. If using, deglaze the pan with sherry or white wine, scraping up any browned bits. Cook until the liquid is nearly evaporated.
  8. Form the Roux: Sprinkle the 1/4 cup (30 g) of flour over the mushroom mixture. Cook, stirring constantly, for 1–2 minutes to cook out the raw flour taste.
  9. Build the Sauce: Slowly whisk in the warm chicken stock until smooth and thick. Then, gradually whisk in the warm milk or half-and-half.
  10. Simmer and Season: Bring the sauce to a gentle simmer, whisking frequently, until it thickens to coat the back of a spoon (about 5 minutes). Season generously with salt and pepper. Taste and adjust.
  11. Combine: Place the blanched green beans into the prepared 9x13 inch casserole dish. Pour the warm crème de champignon sauce evenly over the beans, stirring gently to coat completely.
  12. Bake (Initial): Place the casserole in a preheated oven at 375°F (190°C) for 15 minutes, until the sauce is bubbly around the edges.
  13. Finish and Serve: Remove the dish from the oven. Gently scatter about two-thirds of the crispy fried shallots evenly over the top. Return to the oven for a final 5–10 minutes, just long enough to warm the topping.
  14. Rest: Allow to rest for 5 minutes before serving. Garnish with the remaining crispy shallots just before bringing it to the table for maximum crunch.