Ingredients:
- 4 large Shallots (or 1 large white onion), thinly sliced
- 120 ml / ½ cup Whole Milk or Buttermilk (for soaking)
- 60 g / ½ cup All-Purpose Flour (for dredging shallots)
- 5 ml / 1 tsp Smoked Paprika
- 3 g / ½ tsp Fine Sea Salt (for dredging)
- 500 ml / 2 cups High-Heat Oil (for frying)
- 900 g / 2 lbs Fresh Green Beans (Haricots Verts preferred), trimmed
- 55 g / 4 tbsp Unsalted Butter
- 340 g / 12 oz Cremini (Chestnut) Mushrooms, sliced thinly
- 2 cloves Garlic, minced
- 45 g / ⅓ cup All-Purpose Flour (for roux)
- 480 ml / 2 cups Unsalted Chicken or Vegetable Stock, warmed
- 240 ml / 1 cup Whole Milk or Half-and-Half
- 5 ml / 1 tsp Fresh Thyme leaves (or ½ tsp dried)
- 2 g / ½ tsp Fine Sea Salt (for sauce)
- 1 g / ¼ tsp Freshly Cracked Black Pepper
- Pinch of Freshly Grated Nutmeg
Instructions:
- Prepare Shallots: Slice shallots thinly using a mandoline or sharp knife. Soak them in milk for at least 15 minutes. This helps tenderise them and ensures the flour coating adheres well.
- Blanch the Beans: Bring a large pot of heavily salted water to a rolling boil. Add the trimmed green beans and boil for 3–4 minutes until bright green and tender-crisp (al dente).
- Shock the Beans: Immediately drain the beans and plunge them into an ice bath to stop the cooking process. Drain well and set aside. This step is crucial for color and texture.
- Dredge Shallots: Drain the soaked shallots completely. In a medium bowl, combine the dredging flour, salt, and paprika. Toss the shallots thoroughly until every piece is coated.
- Sauté Mushrooms: Melt the butter in the skillet over medium-high heat. Add the sliced mushrooms and sauté until they release their liquid and begin to brown (about 8–10 minutes). Add the minced garlic and thyme and cook for 1 minute until fragrant.
- Make the Roux: Sprinkle the roux flour over the mushroom mixture. Stir continuously for 1–2 minutes; the mixture should look like wet sand (a blond roux).
- Whisk in Liquid: Slowly whisk in the warmed chicken stock until the sauce is smooth and lump-free. Then, slowly whisk in the milk or cream.
- Simmer and Season: Bring the mixture to a gentle simmer, whisking frequently. Cook until the sauce has thickened sufficiently to coat the back of a spoon (about 5 minutes). Season with salt, pepper, and nutmeg. Taste and adjust seasoning.
- Combine and Transfer: Gently fold the blanched green beans into the creamy mushroom sauce until evenly coated. Pour the mixture into the prepared 9x13-inch casserole dish.
- Bake: Bake in a preheated oven at 180°C / 350°F for 25–30 minutes, or until the sauce is bubbling around the edges and slightly golden on top.
- Fry Shallots: While the casserole bakes, heat the high-heat oil in a deep saucepan to 160°C / 325°F. Working in small batches, fry the dredged shallots until deep golden brown and crisp (2–3 minutes per batch).
- Drain and Season: Remove the shallots with a slotted spoon and place them immediately on a wire rack lined with paper towels. Season lightly with a pinch of extra salt immediately after frying.
- Serve: Remove the hot casserole from the oven. Top generously with the crispy shallots just before serving.