Potato Gratin with Mushrooms and Mascarpone Cheese

We're always looking for great recipe to share with our friends and family, and this one is sure to please.  Another great recipe form our favorite Chef Anita Dillon (dillsand@verizon.net 951-323-1504), she never let's us down.

Serves 6-8

Ingredients:

2 oz dried Porcini mushrooms

1 cup boiling water

2 Tablespoons (1/4 stick) unsalted butter

2 Tablespoons Extra Virgin Olive Oil

1/4 cup plus 2 Tablespoons grated Parmesan Cheese

1 1/2 cups Mascarpone Cheese (from 1 1/2 seven ounce containers)

1 cup whipping cream

3 cloves garlic, chopped

pinch of fresh ground nutmeg

2 1/2 lbs russet potatoes (about 5 large), peeled, cut crosswise into 1/8" slices.

Directions:

place Porcini Mushrooms in a medium bowl and pour 1 cup boiling water over them.  Place smaller bowl on top of mushrooms to keep them under the water.  Let soak for 20 minutes.  drain and chop coarsely. 

Melt butter with olive oil in medium skillet over medium heat.  Add chopped mushrooms and saute until beginning to brown, about 3 minutes.  sprinkle with salt and pepper.  Remove from heat.  Whisk 1/4 cup parmesan cheese, Mascarpone, cream, garlic and nutmeg in a small bowl; season with salt and pepper.  This mushroom and cheese mixture can be prepared 1 day ahead and kept covered in the refrigerator.  

Preheat oven to 325F.  Butter a wide, shallow 2 qt baking dish.  arrange 1/4 of potato slices in bottom of dish, sprinkle lightly with salt and pepper.  scatter 1/4 of mushroom / cheese mixture over this layer.  repeat 3 more times.  sprinkle 2 Tablespoons of parmesan on top.  Place baking dish on cookie sheet.

Bake in middle of oven until top is brown and sauce is bubbling at edges, about 1 hour and 15 minutes.  Let gratin rest 15 minutes before serving.

Can be made 2 hours ahead.  Let stand at room temperature, then tent loosely with foil and reheat in 300F oven for 20 min before serving.