1-1/2 pounds green beans, lightly steamed and cut into halves or thirds
3 tablespoons butter
1 shallot, finely diced
2 cups baby bella mushrooms, sliced
3 tablespoons flour
2 cups milk
1/3 cup parmesan cheese, grated
1/4 -1/2 teaspoon salt
Pepper
Homemade crispy onions straws*
The Pioneer Woman's procedure calls for a candy thermometer. And while a candy thermometer would be useful, it is not necessary. Just give the oil several minutes to get really good and hot. Then, test a very small batch of onions. The oil is hot enough when the coated onions bubble frantically and quickly become golden brown and crispy. The onions can be made a few days ahead of time and stored in an airtight container. They will loose some of their crispiness in the container, but will re-crisp nicely when baked on the casserole!
Preheat oven to 375 degrees F.
Place the steamed and chopped green beans in a large casserole dish. Set aside.
Heat butter in a saucepan over medium heat. Add the chopped shallot and mushrooms. Cook for about 5-7 minutes until they are tender and golden. Sprinkle the flour on top of the mushrooms. Stir and cook for an additional minute. Gradually whisk in the milk. Bring to a simmer and cook for 2-3 minutes, until the mixture begins to thicken. Reduce the heat. Add the Parmesan cheese, salt, and pepper.
Pour the mushroom sauce over the green beans, then give the dish a little shake to help the sauce settle over the beans. Top the mixture with the crispy onion straws and bake for about 20-25 minutes until bubbly hot.
**You can prepare the dish ahead of time up to pouring the sauce over the green beans. Then, cover and refrigerate until preparing to serve. When reheating, allow the beans and sauce to bake for about 10-15 minutes before topping with the crispy onion straws. Once you’ve added the onions, give it another 15-20 minutes to finish baking.
