This recipe originally accompanied Poached Halibut with Black Truffles and Purple-Potato and Crab Gratin .

　　

Ingredients

Serves 6 generously as a side dish

　　1 tablespoon olive oil

　　1 garlic clove

　　1 1/2 cups heavy cream

　　freshly grated nutmeg

　　sea salt

　　freshly ground white pepper

　　1 pound lump crab meat (preferably from Maine)

　　3 pounds purple potatoes*

　　*available at specialty produce markets

　　

Step 1

Preheat oven to 450°F. Brush bottom and side of a 3-quart gratin dish (about 15 by 10 by 2 inches) with olive oil. With flat side of a heavy knife lightly crush garlic and rub over bottom and side of dish.

　　

Step 2

In a small bowl stir together cream and nutmeg, sea salt, and white pepper to taste. Pick over crab meat to remove any bits of shell and cartilage and divide into 3 portions. Peel potatoes and with a mandoline or other manual slicer cut crosswise into 1/8-inch-thick slices. Divide potatoes into 4 portions. In gratin dish evenly arrange 1 portion potatoes and top with 1 portion crab, spreading evenly. Season crab layer with sea salt and white pepper. Repeat layering with remaining portions of potatoes and crab, seasoning each crab layer and ending with potatoes. Pour cream evenly over gratin and press down on top layer of potatoes to briefly submerge them in cream.

　　

Step 3

Bake gratin, covered with foil, in middle of oven 20 minutes. Remove foil and bake gratin until potatoes are tender and lightly browned, about 25 minutes more.