Potato Gratin with Rosemary Crust

Are you mulling over lists for holiday dinners yet? My biggest quandary has always been side dishes...veggies or potatoes...finding something a little different. My family demands mashed potatoes, so year after year they grace the table. Any inventiveness and adventure rested with vegetables or sweet potato dishes; they didn't mind variety there, just as long as I didn't mess with their turkey, mashed potatoes and gravy. 
Now that everyone's older, when I'm doing the cooking at Thanksgiving, I don't even necessarily make a whole turkey, but try things like Ina's stuffed turkey breast  or the Two Fat Ladies chicken. Anything goes. 
For potato-type sides, Ina's Rosemary Roasted Potatoes  were a big hit one year but this year you really must try this gem of a recipe I found recently: Potato Gratin with Rosemary Crust. There is a double crust with rosemary and Gruyere stuffed in between. Very unusual. While the bottom photo looks like this gratin has an overabundance of crust, you can see by the first photo there's not as much crust as you would expect.
Let me sum it up: pretty layers of potatoes, cheesy and delicious. Go ahead, make it for your family...they'll love it. 

Potato Gratin with Rosemary Crust
From Southern Living, December 2010

Ingredients:

1   (14.1-oz.) package refrigerated pie crusts  
1 tablespoon  chopped fresh rosemary  
1/4 teaspoon  freshly ground pepper  
2 cups  (8 oz.) shredded Gruyère cheese, divided  
1 1/2 pounds  Yukon gold potatoes  
1 1/2 pounds  sweet potatoes  
1 teaspoon  kosher salt  
2/3 cup  heavy cream  
1   garlic clove, minced  
  Garnish: fresh rosemary sprigs  

Method: 
Preheat oven to 450°. 
Unroll pie crusts on a lightly floured surface. Sprinkle rosemary, pepper, and 1/2 cup cheese over 1 pie crust; top with remaining pie crust. Roll into a 13-inch circle. Press on bottom and up sides of a 9-inch springform pan; fold edges under. Chill.
Meanwhile, peel and thinly slice Yukon gold and sweet potatoes. I used a mandolin to get thin, even slices.
Layer one-third each of Yukon gold potatoes, sweet potatoes, and salt in prepared crust. Sprinkle with 1/4 cup cheese. Repeat layers twice, pressing layers down slightly to fit.

Microwave cream and garlic in a 1-cup microwave-safe measuring cup at HIGH 45 seconds; pour over potato layers in pan. Sprinkle with remaining 3/4 cup cheese. I was afraid it would leak, so I covered a baking sheet with foil and then placed the springform pan on top. Then cover with heavy-duty aluminum foil.
Bake at 450° for 1 hour. (Yes, that says 450) Uncover and bake 25 minutes longer or until potatoes are done and crust is brown. Let stand 10 to 15 minutes. Carefully transfer to a serving plate, and remove sides of pan. If desired, carefully slide gratin off bottom of pan using a long knife or narrow spatula. Garnish with rosemary sprigs.