Ingredients:

  • 4 large shallots (or 1 medium onion), thinly sliced
  • 3 tbsp all-purpose flour (for shallots)
  • 1 tsp fine sea salt (for shallots)
  • 2 cups neutral oil (e.g., canola, vegetable) for frying
  • 2 lbs (900 g) fresh whole green beans (Haricots Verts preferred), trimmed
  • 4 tbsp (55 g) unsalted butter
  • 1 cup (150 g) sliced cremini mushrooms, wiped clean
  • 1/2 cup (75 g) finely chopped white onion or shallot
  • 3 tbsp (25 g) all-purpose flour (for sauce)
  • 1/2 tsp (2 g) garlic powder
  • 1/2 tsp (2 g) dried thyme
  • 1 1/2 cups (360 mL) chicken stock or mushroom stock, warmed
  • 1 cup (240 mL) whole milk (or half-and-half), warmed
  • 1/4 cup (60 mL) heavy cream
  • 1 tsp (5 g) Worcestershire sauce
  • Salt and freshly ground black pepper, to taste

Instructions:

  1. Step 1: Prepare the Crispy Shallots. Thinly slice the shallots. Toss them vigorously with 3 tablespoons of flour and 1 teaspoon of salt until coated. Heat the neutral oil in a deep pot to 325°F (165°C). Fry the shallots in batches for 3–5 minutes until golden brown and crisp. Remove with a slotted spoon, drain on paper towels, and lightly salt immediately. Set aside.
  2. Step 2: Prepare the Green Beans. Bring a large pot of salted water to a rolling boil. Add the trimmed green beans and cook for 3–4 minutes until tender-crisp. Immediately drain and plunge them into a large bowl of ice water to stop cooking. Drain well and set aside.
  3. Step 3: Make the Creamy Mushroom Sauce (The Roux). Melt the butter in a skillet over medium heat. Add the sliced mushrooms and chopped onion. Sauté until the mushrooms are deeply browned (8–10 minutes). Season lightly.
  4. Step 3 Continued: Sprinkle the 3 tablespoons of flour (for sauce), garlic powder, and thyme over the mixture. Cook, stirring, for 1–2 minutes. Slowly stream in the warm stock, whisking continuously to prevent lumps. Once smooth, slowly whisk in the warm milk and cream.
  5. Step 3 Concluded: Bring the sauce to a gentle simmer until it thickens sufficiently (about 5 minutes). Stir in the Worcestershire sauce. Taste and adjust salt and pepper.
  6. Step 4: Assemble and Bake (First Stage). Preheat the oven to 375°F (190°C). Gently fold the blanched green beans into the creamy mushroom sauce until fully coated. Pour the mixture into a 9x13 inch casserole dish. Cover the dish tightly with foil and bake for 20 minutes.
  7. Step 5: Finish and Serve. Remove the casserole from the oven, remove the foil, and sprinkle two-thirds of the crispy shallots evenly over the top. Return the uncovered casserole to the oven for an additional 10 minutes, or until bubbly. Let rest for 5 minutes. Top with the remaining reserved fresh crispy shallots just before serving.