To Make the Pie Crust
Mix flour and salt in food processor fitted with metal blade.
Cut in butter cubes with five 1-second pulses. Add cold lard and continue cutting in until flour resembles coarse cornmeal with butter bits no bigger than small peas, about 4 additional 1-second pulses. Turn mixture out into a medium-sized bowl.
Use your fingers to quickly sift through the mixture and if you find any really large chunks, just massage with some flour with your fingers to break it up.
Sprinkle 3 Tbsp of ice water over mixture. With a fork, fluff to mix thoroughly. Squeeze a handful of dough — if it doesn’t stick together, add two more tablespoons of water and repeat. Continue adding 1 tablespoon at a time until a quick squeeze of the dough shows it is sticking togeether.
Divide dough into two and then flatten into 6-inch discs. Refrigerate for 30 minutes before rolling. I had better success using a pastry cloth than trying to roll it on my granite top but in either case, make sure you sprinkle counter/cloth with flour and flour your rolling pin.
To Make and Assemble the Pie
In a large bowl, toss together the cherries (if using frozen cherries, they should be frozen; do not thaw), sugar, cornstarch, and salt.
Let the cherry mixture sit for about 20 minutes if using fresh cherries, 60 minutes if using frozen cherries. (If your cherries have developed a lot of juice, you will need to cook the mixture in a saucepan on simmer until the sauce thickens, about 5 minutes; let cool.)
Remove your dough from the fridge. Roll one piece into a circle large enough to fill a 9-10" pie place and fit gently into plate. DO NOT stretch your dough!
Dump the cooled cherry filling into the crust-lined pie plate. Dot the top with the butter evenly over the filling and then make your lattice crust (See notes; easier than you think!)
Trim the dough, roll the edges under and crimp the edges with your fingers or a fork then lightly brush the entire surface of the pastry with the beaten egg. Sprinkle with some sugar; I love using large crystal sugar typically used for cake decorating.
Place the pie on a rimmed baking sheet lined with aluminum foil.
Bake the pie at 425°F (220°C) for 15 minutes. Turn the oven down to 375°F (190°C) and bake until bubbling, at least another 30 minutes (longer if using frozen cherries).
Let the pie cool slightly before slicing and serving.