Chocolate Meringue Pie

Combine 1 1/2 cups (375 ml) of the sugar and the cornstarch in a saucepan. Blend in the milk gradually. Add the chocolate and bring the mixture to a boil over moderate heat, stirring frequently, and boil for 1 minute. Blend half the chocolate mixture into the egg yolks, then add the egg mixture to the pan and cook 3 minutes, stirring constantly. Remove from the heat and stir in the butter, vanilla, and salt. Allow the filling to cool, stirring occasionally to keep it smooth. Pour into the baked pie shell. Beat the egg whites and cream of tartar until foamy. Add the remaining 1/2 cup (125 ml) sugar and continue beating until the egg whites are stiff and glossy. Spread the meringue over the pie, making sure that it touches the pie shell all around. Bake in a preheated 350F (180C) oven for 15 to 20 minutes, until the tips of the meringue are browned. Chill for at least 2 hours before serving.