Ingredients:

  • 5 lbs (680 g) Fresh Green Beans (trimmed and rinsed)
  • 1 tsp (5 ml) Coarse Salt (for blanching water)
  • 4 Tbsp (56 g) Unsalted Butter
  • 1 large (100 g) Shallot (finely diced)
  • 1 lb (450 g) Cremini (Baby Bella) Mushrooms (thinly sliced)
  • 2 cloves Garlic (minced)
  • 1/4 cup (30 g) All-Purpose Flour
  • 5 cups (350 ml) Whole Milk (warmed slightly)
  • 1/2 cup (120 ml) Low-Sodium Chicken or Vegetable Stock
  • 2 Tbsp (30 ml) Dry Sherry or Marsala Wine (optional)
  • 1/4 cup (60 ml) Heavy Cream (35% fat)
  • 1/2 tsp Dried Thyme
  • 1/4 tsp Freshly Grated Nutmeg
  • Salt and freshly cracked Black Pepper (To taste)
  • 2 cups (115 g) Crispy Fried Onions
  • 1 Tbsp (15 g) Unsalted Butter (melted)

Instructions:

  1. Prepare the Green Beans: Bring a large pot of salted water to a rolling boil. Drop the trimmed green beans into the water. Cook for 4–5 minutes until the beans are bright green and tender-crisp (al dente). Immediately drain the beans and plunge them into an ice bath to halt cooking and set the colour. Drain thoroughly and set aside.
  2. Sauté Aromatics: Melt the 4 Tbsp butter in the saucepan over medium-high heat. Add the sliced shallot and sauté until softened (about 2 minutes).
  3. Brown Mushrooms: Add the sliced mushrooms. Sauté vigorously, stirring occasionally, until they have released their liquid and are deeply browned and caramelized (Approx. 8–10 minutes).
  4. Add Garlic and Thyme: Stir in the minced garlic and dried thyme. Cook for 1 minute until fragrant.
  5. Create the Roux: Sprinkle the flour over the mushroom mixture. Stir continuously for 1 minute; the mixture should look thick and pasty. This cooks out the raw flour taste.
  6. Whisk in Liquid: Slowly whisk in the warmed whole milk, followed by the stock, ensuring there are no lumps. The sauce will begin to thicken almost immediately.
  7. Simmer and Season: Bring the mixture to a gentle simmer. Stir in the heavy cream, sherry (if using), nutmeg, salt, and pepper. Taste and adjust seasoning. Remove from heat.
  8. Combine & Transfer: Gently fold the blanched, drained green beans into the prepared mushroom sauce. Pour the mixture evenly into the buttered 9x13 inch casserole dish.
  9. Initial Bake: Bake in a preheated oven at 375°F (190°C) for 20 minutes, or until the sauce is bubbly around the edges.
  10. Finish Topping: In a small bowl, toss the crispy fried onions with 1 Tbsp of melted butter. Remove the casserole from the oven. Spread the buttered crispy onions evenly over the top.
  11. Final Bake and Rest: Return the casserole to the oven for 5 minutes, or until the onions are golden brown and crisp, but not burnt. Let the casserole rest for 5–10 minutes before serving.