Preheat oven to 350 degrees. Combine eggs and cream and season with salt and pepper. Slice potatoes and Jerusalem artichokes on a mandoline or very thinly by hand. In bottom of a baking dish alternately layer potatoes and artichokes. Season with salt and pepper and sprinkle with cheese and sage every few layers. Continue until pan is full. Pour egg mixture over finished dish and press down to insure it soaks all layers. Cover and bake until tender, about 45 minutes.
Yield: 4 servings