Sweet Potato Gratin

Serves: 8 to 12

Ingredients:

For the topping:
1 cup panko bread crumbs
1 cup pecans, chopped
¼ cup Parmigiano
Olive oil for drizzling

For the gratin:
4 lbs. sweet potato
2 lbs. onions, thinly sliced
4 tablespoons unsalted butter
2 cups heavy cream
½ teaspoon salt
½ teaspoon pepper
½ teaspoon cayenne pepper
1 ½ teaspoons fresh thyme

Preparation:
1. Heat the oven to 350°F and arrange a rack in the middle. Butter a 13-by-9-inch baking dish and set aside.
2. Melt butter in a medium frying pan over medium-low heat. When it foams, add onion and season well with salt and pepper. Slowly cook until soft and translucent (about 30 minutes); set aside.
3. Peel sweet potatoes and cut into 1/8″ slices with a mandolin, sharp knife, or food processor with slicer attachment.
4. Mix the cream, cayenne and thyme leaves in a large bowl and set aside.
5. In the baking dish, layer 1/3 potato slices on the bottom, 1/3 cream mixture, add salt and pepper, and ½ of the onions. Repeat, layering another 1/3 of potato slices, 1/3 cream mixture, salt and pepper, and the rest of the onions. Finish off with the last of the sweet potato and cream mixture, and a sprinkle of salt and pepper.
6. Cover with foil and bake 40-50 minutes (it should be soft and cooked through).
7. Combine topping ingredients and sprinkle mixture evenly over gratin. Drizzle with a little olive oil to help with the browning. Bake uncovered, about 10 minutes, until golden. Keep an eye out to make sure the pecans don’t burn.