I came upon a reprint from a 1995 Gourmet magazine for Halloween. The recipe is “below the fold”:
Duchesse Ghost Potatoes
4 pounds large potatoes
3/4 stick (6 tablespoons) unsalted butter, cut into pieces
1 1/4 cups milk
3 large egg yolks
small dark seeds such as black sesame seeds or nigella, cumin seeds or caraway seeds for eyes
1. Peel and quarter potatoes and in a large saucepan cover with salted cold water by 2 inches. Bring water to a boil and simmer potatoes until tender, about 15 minutes
2. While potatoes are simmering, in a small saucepan heat butter with milk over moderately low heat until melted and keep warm.
3. Drain potatoes in a colander and place in a bowl. With an electric mixer beat in milk mixture, yokes and salt and pepper to taste.
4. Preheat oven to 400 F.
5. Spread about one third of the potatoes in a buttered 1 quart gratin dish and transfer remaining potatoes to a pasty bag fitted with a 3/4 inch plain tip. On potatoes in dish pipe potatoes close together into pointed mounds for form “ghosts” and garnish each mound with 2 seeds for ghosts’ eyes. Potatoes may be made up to this point 1 day ahead and chilled, covered loosely.
6. Bake potatoes until heated through and tops of “ghosts” are golden, 15 to 20 minutes
7. Be very afraid.
Serves 6 to 8