Preheat oven to 350 degrees. In a large bowl, Rub the butter into the flour. In a small bowl, beat the egg with half of the sugar, add the egg mixture and the remaining sugar to the butter and flour mixture. Add the salt and nutmeg and mix well. Roll the dough between the palms of your hands to form 18 pieces the size of a walnut; moisten your hands or flour them for rolling the dough. Sprinkle dough pieces lightly with sugar and place 2-3 inches apart on a cookie sheet lined with buttered craft paper. Bake until very lightly browned around the edges and on the bottoms, about 8 minutes. (The tops should be done but not browned.) Remove from oven; transfer to wire rack. Cool completely, then store in airtight container.