1. Preheat the oven to 375°F.

  2. To make the crust: Roll out the pastry to a 13" circle. Use it to line a 9" pie pan that’s at least 1 1/4" deep. Give the crust a tall, crimped edge. Refrigerate the crust while you prepare the fillings.

  3. To make the chocolate filling: Place the chocolate and cream in a microwave-safe bowl. Heat in 40-second bursts until the cream begins to steam and bubble. Remove from the microwave and stir until the chocolate is completely melted and the mixture is smooth. Spread the filling in the pastry-lined pan, smoothing the top. Return the pan to the refrigerator.

  4. To make the vanilla filling: In a medium bowl, whisk together the salt, sugar, cornmeal, and cornstarch. Whisk in the cream and vanilla until smooth. Whisk in the eggs and yolks until thoroughly combined and smooth.

  5. Remove the pie crust from the refrigerator and place it on a baking sheet. Carefully pour the vanilla filling into the shell. Cover the edge of the pie with a crust shield or strips of aluminum foil. Bake for 25 minutes.

  6. Remove the crust shield and continue baking for an additional 20 to 25 minutes, until the filling is set 1 1/2" from the center and the center reads 175°F on a digital thermometer.

  7. To make the topping: About 10 minutes before the pie is done baking, whip the egg whites with the cream of tartar until they turn white. Sprinkle in the sugar with the mixer running. Beat until stiff peaks form. Combine the espresso powder and water until dissolved and beat into the meringue.

  8. Remove the pie from the oven and carefully pipe or spread the meringue on top. Return to the oven and bake for 15 to 20 minutes more, until the meringue is golden brown. Remove from the oven and let cool completely (at least 6 hours) before serving.

  9. Refrigerate any leftovers, covered, for up to five days.