Add a little parmesan and a lot of mushrooms to take this holiday classic to a new level. We used baby shiitake mushrooms to make prep easier by just halving them, or they could be left whole for a bigger mushroom bite.
Green Bean Mushroom Casserole
2 pounds green beans
1 pound baby shiitake (halved)
2 tablespoons oil
6 tablespoons butter
1 teaspoon fresh thyme (minced)
2 shallots (diced)
2 tablespoons flour
1 ¼ cup whole milk
1 ¼ cup heavy cream
5-6 cloves garlic (minced)
¾ cup grated parmesan
Salt and Pepper
1-2 cups fried onions
Preheat the oven to 375 degrees Fahrenheit.
Fill a large pot with water and 1 tablespoon of salt. Bring to a boil over high heat. When boiling, add the green beans and boil for 4 minutes (Note: if your pot is not large enough, just do half of the green beans and then repeat the process with the second half). Drain and run under cold water so that the green beans stop cooking. Remove the ends of the green beans and chop them into 2-inch pieces.
In a large pan on medium high heat, cook the mushrooms in 2 tablespoons of oil for about 6-7 minutes, stirring occasionally. Lower the heat to medium and add 4 tablespoons of butter, thyme, and shallot. Cook for 7-9 minutes or until the mushrooms are very tender and the shallots start to brown. Add salt to taste and remove from heat.
Melt 2 tablespoons of butter into a large sauce pan over medium-low heat. Whisk in the flour and cook for about 4 minutes. It should be golden brown and smell a little nutty. Whisk in the milk and heavy cream. Raise the heat to medium-high and bring to a simmer. Watch the milk carefully so that it does not boil over. Stir often as it cooks until it is thick and bubbling, about 5 minutes. Remove from the heat and stir in the garlic and parmesan. Season with a sprinkle of salt and pepper.
Stir the green beans and mushroom mixture together in a 3-quart baking dish. Pour the cream sauce over the top. Cover with foil and bake for 30 minutes. Remove the foil and bake for another 5-20 minutes or until the top and sides are lightly brown. Top with enough fried onions to thinly cover the green beans and mushrooms. Bake for 5 more minutes to get the onions brown, toasted, and crispy.
Let sit 10-15 minutes before serving. Enjoy!