Preheat the oven to 350ºF.
Peel and thinly slice the potato.
Place 1 pat of the butter in the bottom of each of ramekins. Press 2 slices of the potato on top of the butter, and sprinkle all 4 ramekins with a total of 1/4 teaspoon of the salt and 1 turn each of pepper. Add 2 slices of the shallot, 2 slices potato, 1 slice shallot, 1 slice potato, and 1 pat butter on each. Add another 1/4 teaspoon salt on all 4, and 1 turn each of pepper.
In a bowl, combine the cream with the egg, garlic, nutmeg, the remaining 1/4 teaspoon salt and 2 turns black pepper. Whisk until thoroughly blended. Divide among the ramekins, pouring this custard over the potatoes and shallots.
Place the ramekins in a 2-inch-deep roasting pan. Place the pan on the oven rack and carefully pour 1 inch of the water around the ramekins. Bake until golden brown, for about 1 hour. Remove from the oven and cool to room temperature, for about 20 minutes. Slip the tip of a sharp knife around the side of each custard and turn the ramekins over to unmold. Serve immediately.
Yield: 4 side servings