Why “Chess” Pie? As one story goes, a Southern gentleman came home one evening and asked his wife, an accomplished but modest cook, what smelled so good. “It’s jes’ pie,” she replied.
For crust: I recommend using Dad’s Pie Pastry, but any other pastry will do. Roll the dough into a 13-inch circle and line a 9-½-inch deep-dish pie plate with it, sculpting the overhanging dough into an upstanding rim. Chill and partially prebake the shell. Then cool the shell.
For filling: Preheat the oven to 350ºF. Put the butter into the top of a double boiler over not-quite-simmering water. Add the chocolate. When it is melted, whisk to smooth. Remove the pan insert from the heat and set aside. Mix the sugar, cornmeal, salt, and instant coffee in a large bowl. Add the eggs and yolk, milk, and vanilla. Whisk to blend. Add the chocolate and whisk until smooth. Pour the filling into the pie shell. Bake on the center oven rack for about 50 minutes. When done, the pie will puff up like a squat top hat. Cool on a rack for at least 1 hour before slicing and serving. Serve warm, chilled, or at room temperature. Refrigerate, if not serving within a couple of hours.