CORNMEAL CRUST

Steps:

• Prepare the butter and lard, if using. Cut the butter into 1/2-inch (12-mm) cubes (a bench scraper is perfect for this, but a sharp knife works well too), and cut the lard into small pieces. Return them to the fridge to cool.
• In a liquid measuring cup, stir together the milk and vinegar. Refrigerate the mixture until ready to use.
• On a clean flat surface or in a large shallow bowl, toss the flour, cornmeal, cornstarch, sugar, and salt together lightly to blend. Add the butter and lard (if using) to the dry ingredients and, using the tool of your choice, cut the fat into the flour with speed and patience, until the fat has been reduced to small pea-sized chunks. Try to use a straight up-and-down motion, as the more you press on the flour the more tough gluten will develop. Avoid using your fingers, as the heat from your hands will melt the fat and further encourage gluten development. Unlike with pasta or bread, gluten is the enemy of pie dough, so be gentle, and be quick!
• Once your fat has been cut down to size, spread your mixture out to expose as much surface area as possible. Gently drizzle about half of your milk mixture over the flour, trying to cover as wide an area as you can. Using bench scrapers or a large spoon, lightly toss the flour over the liquid, then spread everything out again, and repeat the process with the second half of the liquid.
• You should now have a dough that will just hold together when pressed against the bowl, with visible little chunks of butter. If you need to add more liquid to bind it, do so with more cold milk, adding a tablespoon at a time until you reach the right texture. It's not an exact science, as everything from the humidity in the air to the dryness of your flour will affect the consistency of your dough.
• Once you've reached your goal, cover the dough tightly in plastic wrap and refrigerate it for at least 1 hour. The dough can be kept in the fridge for up to 1 week, well wrapped, or in the freezer for up to 2 months.