Is this dish kind of a pain in the ass? Yes, definitely. But when there are so many amazing varieties of mushrooms at the market, it's totally worth the effort.
For 4 Servings
For the filling:
1 pound butternut squash, peeled and cut into 1/2-inch dice
1/4 cup olive oil
2 tablespoons chopped sage
1/2 teaspoon cinnamon
Salt and pepper
1/4 pound black trumpet mushrooms, rinsed and sliced
1/4 pound chanterelle mushrooms, rinsed and sliced
1/4 pound lobster mushrooms, rinsed and sliced
1/4 pound crimini mushrooms, you guessed it: rinsed and sliced
For the sauce:
2 sticks butter ( 1/2 pound)
1 1/4 cups all purpose flour
2 1/2 cups whole milk, warmed
1/2 teaspoon nutmeg
8 ounces mascarpone or cream cheese
Butter or Olive oil for greasing the pan
8 sheets of pasta rolled to about 8x 10 inches-- purchased or homemade (you can use this recipe-- just roll into rectangles instead of cutting into pappardelle)
1/2 cup grated Parmesan, or more.
1. Heat oven to 350 degrees. Toss the squash with 1/4 cup olive oil, sage, cinnamon, salt and pepper. Spread in one layer on a baking sheet. Bake until squash is soft, about 45 minutes. Set aside.
2. Heat one stick of butter in a large skillet over medium heat. When it melts, add mushrooms. Stir to cover the mushrooms in butter, then let cook without stirring until the mushrooms begin to release liquid. Reduce heat to low, stirring occasionally, for at least 30 minutes, until mushrooms begin to brown. Season with salt and pepper and set aside.
3. Make béchamel sauce. Heat remaining stick of butter in a saucepan over medium heat. When it melts, gradually whisk in the flour until it is incorporated. Cook, whisking continually, until flour browns a bit, about 5 minutes. Stir in some salt, pepper and nutmeg. Add milk 1/4 cup at a time, whisking after each addition until smooth. Cook over low heat, stirring frequently, for about 15 minutes. Whisk in mascarpone or cream cheese, and take the sauce off heat.
4. Bring a large pot of heavily-salted water to a boil. Cook pasta rectangles, a few at a time, until they just begin to float-- about 30 seconds. Remove the rectangles and plunge into ice water to stop cooking.
5. Place 1/4 cup olive oil in large skillet over high heat. Add the broccoli rabe and a large pinch of salt. Cook until leaves wilt slightly. Remove with a slotted spoon.
6. To assemble: Grease a large baking pan generously, then put the rabe to coat the bottom. Heat oven to 350 degrees. Work with 2 or 3 pasta rectangles at a time. Put them on a work surface, long end facing you. Smear a layer of béchamel along that end. Top with a portion of mushrooms and squash. Roll up the long way, enclosing ingredients. As you finish each roll (you should have 8), place it in a baking pan. When all cannelloni are made, dot with remaining butter and pour over remaining bechamel. If the sauce looks a little thick, you can thin it with a little of the pasta- cooking water. Sprinkle with half the Parmesan. At this point you can refrigerate the pan of cannelloni until ready to bake. Remove the pan from the fridge about a half hour before baking to bring it to room temperature.
7. Bake, covered with foil for about 20 minutes, then remove foil and bake until cheese is nicely bubbly and brown. You can also broil the top to speed this process along.
8. Sprinkle cannelloni with fresh sage, and pass remaining parmesan at the table.