STUFFED SHELLS WITH MUSHROOM SAUCE

1 pound manicotti or giant shells, uncooked
FOR THE MUSHROOM SAUCE:
1 ounce dried porcini mushrooms, soaked in 4 cups warm water for at least 30 minutes
1 pound white button mushrooms, rinsed and sliced
6 tablespoons butter
2 to 3 tablespoons flour
1 pint half-and-half or heavy cream
1/2 teaspoon kosher salt
Ground white pepper to taste
1/4 teaspoon grated nutmeg
1/2 cup grated parmesan cheese
FOR THE PASTA FILLING:
2 eggs, lightly beaten
1 pound ricotta cheese
1 cup shredded mozzarella cheese
1 package (10 ounces) frozen chopped spinach, defrosted and squeezed to remove excess moisture
1 cup walnuts, toasted and chopped
Kosher salt and fresh ground pepper to taste
1 cup grated parmesan or Asiago cheese

TO MAKE THE MUSHROOM SAUCE:
Melt 4 tablespoons of the butter in a large, heavy saucepan over low heat. Add the sliced button mushrooms and saute until they're soft and all the moisture has been released from the mushrooms and has evaporated.

Add the remaining 2 tablespoons butter to the sauteed mushrooms. Allow it to melt over medium heat. Add the flour, stir well, and cook for 5 minutes.

Add the porcini mushrooms, along with the water they were soaked in (all but the gritty bits in the bottom of the bowl). Cook for 5 minutes over medium heat.

Add the half-and-half, salt, white pepper and nutmeg. Simmer for 15 to 20 minutes.

Add the parmesan, stir, and cook over low heat for an additional 5 to 10 minutes. The sauce is done when it has thickened slightly.

TO MAKE THE FILLING:
In a mixing bowl, combine the eggs, ricotta, mozzarella, spinach, walnuts and salt and pepper. Stir in 3/4 cup of the parmesan. Cover and chill until needed.

TO ASSEMBLE AND BAKE:
Preheat the oven to 375 degrees F.

Cook the manicotti or giant shells for a few minutes less than specified in package directions. Drain, let cool, then fill the shells with the ricotta mixture.

Arrange the shells in a casserole or baking dish so they touch but are not crammed in. Pour or spoon the sauce over the shells so they are almost covered. Sprinkle the top of the dish with the remaining 1/4 cup parmesan.

Bake until the top is browned and the sauce is bubbling, about 40 minutes.

Source: The Big Platter Cookbook: Cooking and Entertaining Family Style by Lou Jane Temple and A. Cort Sinnes