Scalloped Russet and Sweet Potato Gratin with Fresh Herbs

This is the perfect side dish for your Thanksgiving meal.  The recipe has been on my to do list since it appeared in Bon Appetit in 2008.  I just loved the idea of using two kinds of potatoes with Gruyère cheese.  It had to be a winner.  I’m not a fan of the sweet potato souffle which I think  belongs on the dessert table.  It is much too sweet as a side dish to my beautiful turkey and dressing. My pantry is overflowing with sweet potatoes from my CSA box. so I finally got around to making the dish.  I first tried it out on my book club and they loved it.  It has a hint of  sweetness, but the two types of potatoes definitely make this dish stand out!  Let’s not forget the fresh herbs, cream and butter that take the dish to the next level.  Oh, my goodness I can just make a meal out of this!

Before the potatoes are sliced have all of the other ingredients prepped including the sauce.   If you have a mandolin use it to slice the potatoes, but I found that my food processor with the slicer blade worked perfectly.   I do have a scale and weighed the potatoes first.  I used 2 very large Russet potatoes and 3 medium sweet potatoes  scrubbing them before peeling.  I worked with the sweet potatoes first then the russets. The russets will  turn dark.  If you are not able to work quickly the potatoes can be placed in cold water.   Do this as a last resort  because it will remove part of the starch that thickens the sauce.  I have made this dish several times one with not so good results.  I didn’t have enough russet potatoes so I just pulled what I had in my pantry which was a few all-purpose potatoes.  These potatoes do not have as much starch as Russets resulting in a dish that curdled.  It was still edible,  but not very pretty.  Stick to Russett potatoes or Yukon Golds for the best results.  Now get ready  for some of the best potatoes that you have ever had.

Here are the Russets sliced.

Here are the sliced sweet potatoes.

Layered with herbs, salt and pepper

Ready for the oven.

Right out of the oven!

Scalloped Russet and Sweet Potato Gratin with Fresh Herbs Bon Appetit November 2008

• 1 1/2 pounds Russet Potatoes
• 1 1/2 pounds sweet potatoes
• 2 cups whipping cream
• 1/4 cup (1/2 stick) butter
• 2 garlic cloves, minced
• 1 tablespoon minced fresh Italian parsley
• 1 tablespoon minced fresh rosemary
• 1 tablespoon minced fresh thyme
• 1 1/2 teaspoon fine sea salt
• 3/4 teaspoon freshly ground  black pepper
• 1 1/4 cups (packed) coarsely grated Gruyère cheese ( about 5 ounces)

1. Butter 13x9x2 inch glass baking dish.
2. Combine cream, butter, and garlic in medium saucepan.  Bring to a simmer and remove from heat.
3. Mix all the herbs in a small bowl.
4. Mix salt and pepper in another small bowl.
5. Scrub all potatoes and dry with paper towel.  Do this so that you will not have to wash potatoes after peeling them.
6. Working quickly using a food processor slice potatoes.  If you do not have a food processor and cannot work quickly, as you cut the potatoes place them in a bowl of cold water.  This will keep them from turning dark. When you are ready to put the dish together.  Drain and pat the potatoes dry with towels.
7. Transfer half of the potatoes to the baking dish.  Sprinkle with salt and pepper, half of the herb mixture.
8. Sprinkle with half of the cheese.
9. Repeat with the remaining potatoes, salt and pepper, herb mixture, and cheese.
10. Pour cream mixture over gratin, pressing lightly to submerge potato mixture as much as possible.
11. Preheat oven to 400° .
12. Cover gratin tightly with foil.
13. Bake for 30 minutes.
14. Uncover; bake until top of gratin is golden and most of liquid is absorbed about 25 minutes longer.
15. Let stand 10 minutes before serving.