Ingredients:

  • 3 large shallots, thinly sliced (about 3 cups)
  • 3 Tbsp all-purpose flour (for coating shallots)
  • Kosher salt & fresh black pepper, to taste
  • 3 cups neutral oil (e.g., Rapeseed or Peanut), for frying
  • 2 lbs fresh green beans (Haricot Verts), trimmed
  • Water & salt (for blanching)
  • 4 Tbsp unsalted butter, divided
  • 12 oz sliced mushrooms (Cremini/Button)
  • 2 cloves garlic, minced
  • 4 Tbsp all-purpose flour (for the roux)
  • 2 cups whole milk, warmed slightly
  • 1 cup low-sodium chicken or vegetable stock
  • ½ cup heavy cream (double cream)
  • ½ cup Parmesan cheese (freshly grated), optional
  • 1 tsp Worcestershire sauce
  • ½ tsp dried thyme

Instructions:

  1. Prepare the Crispy Shallots: Toss the thinly sliced shallots with the 3 Tbsp of flour, a pinch of salt, and pepper until lightly coated.
  2. Heat oil in a deep-sided skillet to 325–350°F (160–175°C). Working in batches, fry the shallots until deep golden brown and crisp (3–5 minutes per batch). Do not overcrowd the pan.
  3. Drain: Remove shallots with a slotted spoon and immediately place them on a paper towel-lined wire rack. Sprinkle with extra salt while warm. Set aside.
  4. Blanch 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 bright green and tender-crisp (al dente).
  5. Shock the beans: Immediately drain the beans and plunge them into an ice bath to stop the cooking process and retain their vibrant colour. Drain well and set aside.
  6. Create the Scratch Mushroom Sauce: Melt 2 Tbsp of butter in a medium saucepan over medium-high heat. Add the sliced mushrooms and sauté until they have released their liquid and browned beautifully (about 8–10 minutes). Season lightly. Add the minced garlic and cook for 1 minute until fragrant. Remove mushroom mixture from the pan and set aside.
  7. Make the Roux: Return the saucepan to medium heat. Melt the remaining 2 Tbsp of butter. Whisk in the 4 Tbsp of flour. Cook, stirring constantly, for 2 minutes to cook out the raw flour taste.
  8. Add Liquids: Slowly whisk in the warmed milk, followed by the stock, ensuring no lumps form. Bring to a simmer, stirring until the sauce thickens significantly (about 5 minutes).
  9. Finish Sauce: Reduce the heat to low. Stir in the heavy cream, Worcestershire sauce, thyme, and Parmesan (if using). Add the sautéed mushroom mixture back to the sauce. Taste and season robustly with salt and pepper.
  10. Assemble: Preheat oven to 375°F (190°C). Gently fold the blanched, dried green beans into the creamy mushroom sauce in the saucepan.
  11. Initial Bake: Pour the mixture evenly into the prepared casserole dish. Bake the casserole, uncovered, for 20 minutes until the sauce is bubbly and heated through.
  12. Add Topping: Remove the casserole from the oven. Sprinkle the crispy fried shallots evenly over the top.
  13. Final Bake: Return to the oven for a final 10–15 minutes, until the topping is toasted and the casserole is piping hot. Let rest for 5 minutes before serving.