Ingredients:

  • 5 lb Fresh Green Beans (trimmed)
  • 1 tbsp Kosher Salt (for blanching water)
  • 4 tbsp Unsalted Butter
  • 2 medium Shallots (finely diced)
  • 8 oz Cremini Mushrooms (thinly sliced)
  • 4 tbsp All-Purpose Flour
  • 2 cups Whole Milk (lukewarm)
  • 1/2 cup Vegetable or Chicken Stock
  • 1 tsp Fresh Thyme Leaves (picked)
  • 1/2 tsp Garlic Powder
  • Pinch Nutmeg (freshly grated)
  • 1 tsp Kosher Salt
  • 1/2 tsp Black Pepper
  • 2 cups Prepared Crispy Fried Onions

Instructions:

  1. Preheat oven to 375°F (190°C). Grease the 9x13 inch baking dish lightly with butter or cooking spray.
  2. Bring a large pot of salted water to a rolling boil. Add the trimmed green beans and cook for exactly 4 minutes. Immediately drain the beans and plunge them into a large bowl of ice water to shock them. Drain thoroughly and set aside.
  3. Melt the 4 tbsp of butter in the large skillet over medium heat. Add the diced shallots and sauté until translucent (about 3 minutes).
  4. Add the sliced cremini mushrooms to the pan. Increase heat slightly and cook until the mushrooms have released their liquid and browned nicely (about 5-7 minutes). Season lightly with salt and pepper.
  5. Sprinkle the 4 tbsp of flour over the cooked shallots and mushrooms. Stir constantly for 1 minute to cook out the raw flour taste (making the roux).
  6. Slowly whisk in the lukewarm milk, followed by the stock, ensuring no lumps form.
  7. Bring the mixture to a gentle simmer, whisking occasionally. Reduce the heat to low and cook until the sauce is thick enough to coat the back of a spoon (about 5 minutes).
  8. Stir in the fresh thyme, garlic powder, grated nutmeg, remaining salt, and pepper. Taste and adjust seasoning as needed.
  9. Add the blanched green beans to the mushroom sauce and toss gently until fully coated.
  10. Pour the entire mixture into the prepared baking dish.
  11. Bake for 15 minutes, or until the sauce is bubbly and hot throughout.
  12. Remove the casserole from the oven and sprinkle 1.5 cups of the crispy fried onions evenly over the top.
  13. Return the casserole to the oven for an additional 5 minutes, just until the crispy onions are warmed through and the edges of the casserole are golden.
  14. Garnish immediately with the remaining 1/2 cup of crispy onions for extra crunch right before serving.