Ingredients:

  • 2 lbs Fresh Green Beans (haricot verts preferred)
  • 1 Tbsp Kosher Salt (for boiling)
  • 4 Tbsp Unsalted Butter, divided
  • 8 oz Fresh Cremini (Baby Bella) Mushrooms, sliced
  • 1 large Shallot, finely minced
  • 2 cloves Garlic, minced
  • 4 Tbsp All-Purpose Flour
  • 1 cup Chicken or Vegetable Stock (low sodium)
  • 1 1/2 cups Whole Milk or Half-and-Half
  • 1 tsp Worcestershire Sauce
  • 1/2 tsp Dried Thyme
  • 1/2 tsp Freshly Ground Black Pepper
  • 1 tsp Kosher Salt (for sauce, or to taste)
  • 6 oz Crispy Fried Onions (store-bought standard)
  • 2 Tbsp Freshly Grated Parmesan Cheese (optional)

Instructions:

  1. Bring a large pot of heavily salted water to a rolling boil. Drop the trimmed green beans into the water. Cook for 4-5 minutes until they are bright green and tender-crisp (al dente).
  2. Immediately drain the beans and plunge them into a large bowl of ice water to stop the cooking process and preserve their colour. Drain thoroughly and set aside.
  3. Melt 2 Tbsp of the butter in a large skillet over medium-high heat. Add the sliced mushrooms. Cook until golden brown and they have released and reabsorbed their liquid (about 6-8 minutes).
  4. Reduce heat to medium. Add the minced shallot and cook for 2 minutes until translucent. Stir in the minced garlic and thyme, cooking for 1 minute until fragrant. Remove mushroom mixture from the pan and set aside.
  5. Melt the remaining 2 Tbsp of butter in the same skillet. Whisk in the flour and cook for 1-2 minutes, stirring constantly to create the roux.
  6. Slowly whisk in the cold chicken stock until smooth. Then, slowly whisk in the whole milk/half-and-half. Bring the mixture to a simmer, stirring continuously.
  7. Reduce heat to low and allow the sauce to thicken slightly. Stir in the Worcestershire sauce, Kosher salt, and black pepper.
  8. Fold the reserved mushroom mixture back into the béchamel. Taste and adjust seasoning as needed.
  9. Preheat oven to 375°F (190°C). Gently fold the blanched green beans into the creamy mushroom sauce until evenly coated.
  10. Pour the mixture into the prepared 9x13 inch baking dish.
  11. Bake uncovered for 20 minutes, or until the sauce is bubbly and the beans are heated through.
  12. Remove the casserole from the oven. Sprinkle the crispy fried onions and the optional Parmesan cheese evenly over the top.
  13. Return to the oven for an additional 5-10 minutes, just until the crispy onions are golden brown and perfectly crunchy. Watch carefully to prevent burning.
  14. Let the casserole rest for 5 minutes before serving hot.