1 pound sliced mushrooms

1 ½ pound blanched green beans

¼ cup diced yellow onion

1 tablespoon vegetable oil

2 tablespoons unsalted butter

2 tablespoons AP flour

½ teaspoon thyme

¼ teaspoon cayenne pepper

¼ teaspoon nutmeg

1 teaspoon fresh garlic minced

1 cup chicken stock

½ cup heavy cream

1 cup sour cream

¼ cup parmesan cheese, plus 2 tablespoon for topping the Casserole

Salt and pepper to taste

1 cup crispy fried onions (store bought works great and saves you a step) 

Start with a medium sized pot at medium high heat. Add the oil and butter. When the butter has melted add the onions and mushrooms. Sweat these ingredients for 3 minutes stirring occasionally. Next add the garlic then slowly shake the flour over the mixture while stirring. Cook together for 1 minute then add the chicken stock, cream, thyme, cayenne pepper and nutmeg. Bring to a simmer for 3 minutes then add the parmesan cheese. Give the cheese time to melt into the sauce stirring frequently. Remove from the heat then add the sour cream. Mix well then add the salt and pepper. Taste the mixture and adjust seasoning.

Fold blanched green beans into the mixture. Taste and adjust again with salt and pepper if necessary. Place mixture in an ovenproof dish then top with 2 tablespoons of parmesan cheese and fried onions.

Bake at 425 degrees F until golden brown and hot.