SWEET POTATO GRATIN
2 tablespoons unsalted butter
1 large shallot, minced
3 cloves garlic, minced or pressed
2½ cups heavy cream
2 to 3 sprigs fresh thyme
½ teaspoon salt
Fresh ground pepper
3 large sweet potatoes, peeled and sliced into ⅛-inch rounds
½ cup grated Parmesan cheese
2 tablespoons butter
1 cup panko breadcrumbs
¼ cup Parmesan cheese
½ teaspoon smoked paprika
1 tablespoon freshly chopped sage, parsley, or rosemary--or a combination
Preheat oven to 400 degrees Fahrenheit if you plan to use a regular oven. Saute shallot and garlic in the 3 tablespoons butter. Add the cream and pepper to taste and bring to a simmer, keep hot.
Peel the potatoes and slice them in ⅛-inch discs. Discs should be as even in width as possible so that they cook evenly.
Pour ½ cup of the cream into a shallow baking dish. (I used a 9x12 Pyrex dish.) Add one-third of the sweet potatoes to the dish in an even layer. Add another ½ cup of the cream and ¼ cup grated Parmesan. Top with a second layer of potatoes, followed by ½ cup cream and ¼ cup grated Parmesan. Finish with the remaining potatoes, and pour the remaining cream over the top of the gratin.
Cover the baking dish tightly with foil and bake for 50 minutes or until the potatoes are very tender when pierced with a sharp knife. You can also microwave the casserole, covering it with plastic wrap instead of foil. I used the "potato" setting on my oven and ended up doing three cooking times. Either way, test the potatoes to be sure they are tender.
While gratin is in the oven, prepare the crunchy topping. Heat the butter in a large pan. When melted, add the panko and stir until the breadcrumbs are well coated. Continue cooking, stirring constantly, until the panko is golden brown. Transfer the toasted panko to a bowl to cool. When cool, mix in the grated Parmesan and smoked paprika. If you microwaved the casserole, you'll now need to turn on the oven to 400.
After the gratin has baked, remove the foil or plastic wrap. Add the topping in an even layer. Return the gratin to the oven for another 10 to 15 minutes, until the top is crispy and browned and most of the liquid has been absorbed. Allow it to rest for 10 minutes before serving.