Ingredients:
- 1 kg Fresh Green Beans, trimmed and cut into 1-inch pieces
- 1 Tbsp Salt (for blanching water)
- 4 large Shallots, thinly sliced (or 2 medium onions)
- 1/2 cup All-Purpose Flour (for dusting shallots)
- 1/2 tsp Kosher Salt
- 4 cups Vegetable Oil (for frying)
- 4 Tbsp Unsalted Butter
- 250 g Cremini Mushrooms, sliced thinly
- 2 cloves Garlic, minced
- 4 Tbsp All-Purpose Flour (for the roux)
- 1 cup Chicken or Vegetable Stock, low sodium
- 5 cups Heavy Cream (Double Cream)
- 1/2 cup Whole Milk
- 1 tsp Dijon Mustard
- 1 tsp Worcestershire Sauce
- 1 tsp Fresh Thyme Leaves, chopped
- Salt and Black Pepper, to taste
Instructions:
- Prepare the Beans: Bring a large pot of heavily salted water to a rolling boil. Add the trimmed green beans. Cook for 3–5 minutes until tender-crisp (al dente).
- Shock: Drain the beans immediately and transfer them to an ice bath to stop the cooking process and retain their vibrant green colour. Drain well and set aside.
- Prepare Shallots: Toss the sliced shallots with the 1/2 cup flour and salt until lightly coated. Heat the oil in a deep pot to 325°F (160°C).
- Fry Shallots: Working in batches, carefully add the shallots to the hot oil. Fry for 4–6 minutes, stirring occasionally, until deeply golden brown and crisp. Remove immediately with a slotted spoon and spread on a wire rack or paper towels. Season lightly with extra salt while still hot.
- Reserve 1/3 of the fried shallots for mixing into the casserole base. Reserve the remaining 2/3 for the final topping.
- Start Sauce: Melt the butter in a large skillet over medium-high heat. Add the sliced mushrooms and sauté until they release their moisture and start to brown (about 5–7 minutes). Add the minced garlic and thyme and cook for 1 minute until fragrant.
- Make the Roux: Sprinkle the 4 Tbsp flour over the mushroom mixture and cook, stirring constantly, for 1–2 minutes to cook out the raw flour taste.
- Whisk in Liquids: Slowly whisk in the chicken/vegetable stock until smooth. Gradually whisk in the whole milk and heavy cream.
- Simmer and Season: Bring the sauce to a gentle simmer, stirring occasionally, until it thickens sufficiently to coat the back of a spoon (about 5 minutes). Reduce heat to low. Stir in the Dijon mustard, Worcestershire sauce, salt, and pepper. Taste and adjust seasoning.
- Assemble: Gently fold the blanched green beans and the reserved 1/3 portion of crispy shallots into the mushroom sauce.
- Bake: Pour the mixture into the prepared 9x13 inch casserole dish. Bake in a preheated oven at 375°F (190°C) for 20 minutes, or until bubbling hot throughout.
- Top and Finish: Remove the casserole from the oven. Sprinkle the reserved crispy shallots evenly over the top. Return the casserole to the oven for a final 5 minutes to reheat the topping slightly. Serve immediately.