Ingredients:
- 1 kg (2.2 lbs) Fresh Green Beans, trimmed
- 1 Tbsp (15 ml) Kosher Salt (for blanching water)
- 60 g (4 Tbsp or 1/4 cup) Unsalted Butter
- 2 medium Shallots, finely minced
- 225 g (8 oz) Cremini (baby bella) Mushrooms, thinly sliced
- 2 cloves Garlic, minced
- 45 g (1/3 cup) All-Purpose Flour
- 500 ml (2 cups) Chicken or Vegetable Stock, warmed
- 250 ml (1 cup) Heavy Cream (Double Cream)
- 1 tsp (5 ml) Worcestershire Sauce
- 1/2 tsp Dried Thyme
- Pinch of freshly grated Nutmeg
- Salt and Freshly Ground Black Pepper, to taste
- 170 g (6 oz) Crispy Fried Onions
Instructions:
- Blanch the Beans: Bring a large stockpot of water (seasoned with the 1 Tbsp salt) to a rolling boil. Add the trimmed green beans and cook for exactly 3-4 minutes until bright green and tender-crisp (al dente).
- Shock and Drain: Immediately plunge the beans into a large bowl of ice water to halt the cooking process and preserve color and texture. Drain thoroughly and set aside.
- Sauté Aromatics: Melt the 60g butter in a saucepan over medium heat. Add the minced shallots and cook until soft and translucent (about 3 minutes).
- Cook Mushrooms: Add the sliced mushrooms. Increase heat slightly and cook until all the liquid released by the mushrooms has evaporated and they begin to brown slightly (about 8-10 minutes). Add the minced garlic during the final minute.
- Make the Roux: Sprinkle the flour over the mushroom mixture. Stir continuously for 1 minute to cook out the raw flour taste.
- Create the Sauce Base: Gradually whisk in the warm stock until smooth and lump-free. Bring the mixture to a simmer; it will thicken instantly.
- Finish the Sauce: Stir in the heavy cream, Worcestershire sauce, dried thyme, and nutmeg. Simmer gently for 2-3 minutes, stirring occasionally, until the sauce coats the back of a spoon.
- Seasoning Check: Taste the sauce and adjust salt and pepper. Remove from heat.
- Combine: Gently fold the blanched green beans into the creamy mushroom sauce until they are evenly coated.
- Transfer: Pour the mixture into the prepared 9x13 inch baking dish.
- Initial Bake: Preheat oven to 190°C (375°F). Bake the casserole, uncovered, for 15-20 minutes, or until the edges are bubbling.
- Add Topping: Remove the casserole from the oven. Evenly sprinkle the crispy fried onions over the top.
- Final Bake: Return the casserole to the oven for 5-10 minutes, or until the onions are golden brown and perfectly crunchy. Keep a close eye on them to prevent burning.
- Serve: Allow the casserole to rest for 5 minutes before serving.