Preheat the oven to 375 degrees F. In a large saute pan, over medium heat, melt the butter. Add the plums and saute for 2 minutes. Stir in the sugar, cinnamon and salt. Continue to saute for 2 minutes. Whisk the water and cornstarch together. Mix well. Stir the water mixture into the plum mixture. Bring the liquid to a gentle boil and cook for 2 minutes. Remove from the heat and cool completely. In a mixing bowl, combine the flour, salt, and sugar. Add the lard and work it in with your hands until the mixture resembles coarse crumbs. Add the water, 1 tablespoon at a time, and work it in with your hands, forming a smooth ball of dough. Divide the dough in half and wrap each ball in plastic wrap. Refrigerate the dough for 30 minutes. Remove the dough from the refrigerator and let the dough sit out for 5 minutes before rolling out. Roll out each dough on a floured surface into a circle about 12 inches in diameter and 1/8-inch thick. Cut each round of dough out into 6 (6-inch) rounds. Gently fold 6 circles of dough and unfold each round into a 4-inch individual pie pan. Pour 3/4 cup of the filling into each pastry shell. Place the remaining 6-inch rounds over the filling, trimming off the excess. Crimp the edges of the pie crust, sealing the pie completely. Place the pies on a baking sheet and bake until golden brown, about 25 minutes. Remove from the oven and cool for 5 minutes, before serving. Serve each pie with a scoop of ice cream.