Serves six to eight

1 pound sweet potato (about 1 large)

1¼ pounds white potatoes (about 3 medium)

½ teaspoon powdered mustard

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½ teaspoon salt

¼ teaspoon freshly ground black pepper

1 teaspoon nutmeg

1½ tablespoons flour

1 cup shredded Swiss cheese

1 egg

1 cup half-and-half, heated

2 tablespoons cold butter

1. Peel the sweet potato and white potatoes. Slice thinly.

2. Combine the powdered mustard, salt, pepper, nutmeg and flour.

3. Grease a 2-quart shallow baking dish. Place a layer of white potatoes in the bottom of the dish. Sprinkle with half of the flour mixture and a third of the cheese. Top with all of the sweet potatoes; sprinkle with the remaining flour mixture and another third of the cheese. Top with the remaining white potatoes.

4. Whisk the egg in a bowl. Pour in the hot milk, whisking constantly. Pour over the potatoes and sprinkle with the remaining cheese. Dot with the butter. Cover and bake in a preheated 375-degree oven 40 minutes. Uncover and continue baking 15 minutes, or until the potatoes are tender and the top is golden. Let cool 10 minutes before serving.

Adapted by The Seattle Times in 1993 from “The Essential Root Vegetable Cookbook” by Sally and Martin Stone.