Print Recipe

Green Bean Casserole

Servings: 8

Ingredients

  • 6 tbsp butter
  • 1 yellow onion, diced
  • 1 red bell pepper, seeded and diced
  • 1 lb crimini or baby bella mushrooms, sliced
  • 2 tsp sea salt
  • 1/2 tsp freshly ground pepper
  • 1 lb frozen green beans
  • 1/4 cup all-purpose flour
  • 2 cups whole milk
  • 1 pinch cayenne pepper
  • 1 pinch grated nutmeg
  • 1/2 cup gruyere cheese
  • 1/2 cup parmigiano reggiano
  • Crispy fried onions

Instructions

  • Preheat the oven to 375. Butter a large baking dish and set aside.
  • Next, do yourself a favor and prepare your mise en place. Basically this is a fancy French term for “everything in place.” As in, dice the onion and bell pepper and chop up the mushrooms so everything is ready to go.
  • Next, melt two tablespoons of butter in a heavy skillet over medium heat. Sautee the onions until they are softened and translucent, about 3-4 minutes.
  • Toss in the bell pepper and mushrooms and stir everything together.Let the veggies cook until most of the liquid has evaporated, about 8-10 minutes.
  • Next, cook the green beans according to the instructions on the package. (I prefer the stovetop method, but if you want to microwave them, no judgment here).
  • Once they are cooked, add the green beans to a bowl of ice water. This will prevent them from continuing to cook and prevents mushiness.While the green beans are cooling off, grate the cheeses. Sample accordingly. Mmmmm. Gruyere.
  • Drain the green beans and add them to the rest of the veggies, mixing to combine. Add a little salt and pepper to taste. Set aside.
  • Add the remaining 4 tablespoons of butter to a large saucepan over medium heat. Want to save yourself from doing more dishes? Use the same saucepan used to cook the green beans.
  • Once the butter has melted, add ¼ cup flour and whisk constantly until the mixture begins to turn golden brown. Congratulations – you just made a roux. (Hint: a roux is also the key to delicious turkey gravy – it’s essentially a thickening agent).
  • Add the milk in batches and continue to whisk. This part requires a little muscle and a lot of patience, but it will result in a delicious, creamy sauce. Also known as a béchamel. This is the foundation for most creamy sauces (and the basis for the most decadent macaroni and cheese you will ever indulge in… but that’s a recipe for a different day).
  • Add a little salt, pepper, cayenne pepper and nutmeg. Then stir in most of the cheeses, reserving a little for later. Taste. Swoon.
  • Pour the cheese sauce into the veggie mixture and toss to combine thoroughly.
  • Add the veggie mixture to the baking dish. Top with the remaining cheeses.
  • Now it’s time for the finishing touch – the crispy fried onions. I love the Trader Joe’s brand, but you really can’t go wrong here.
  • Cover with foil and bake for 20 minutes at 375. Remove the foil and continue to bake for an additional 10-20 minutes until browned and bubbly.
  • You can also make the green bean casserole up to one day ahead. Just be sure to bring it to room temperature before baking
  • Serve. Enjoy. Fight your loved ones for the last portion. It’s THAT good.

Notes