Make the dough: Place the lard and butter in a bowl and chill in the freezer for at least 30 minutes.
Measure the flour and salt into the bowl of a food processor fitted with a metal blade. Add the chilled lard and butter using a spatula or spoon.
Do not touch the fat, as you want to keep it as cold as possible. Pulse six or more times, until the dough forms pea-sized lumps.
Transfer the mixture to a bowl, make a well in the center and add ice water 1 tablespoon at a time, stirring with a Danish dough whisk or a fork, until the dough just comes together. With lightly floured hands, quickly press the dough into a disk, wrap with plastic wrap and refrigerate for at least 1 hour.
Just before making the pie filling, roll the dough out on a lightly floured pastry cloth to a 12-inch circle and transfer to a 9-inch glass pie dish, leaving a 1-inch overhang. Decoratively crimp the edges of the dough. Preheat oven to 350° F.
Make the filling: In a stand mixer, beat the eggs on low speed, slowly sprinkling in the sugar 1 tablespoon at a time to fully incorporate. With the mixer still on low, add the bourbon and salt, then drizzle in the sorghum and melted butter.
Remove the bowl from the stand and stir in the chopped pecans. Pour into the piecrust and arrange whole pecans on top.
Bake for 30 minutes, then cover the outer edge of the piecrust with a crust protector or foil to keep it from burning. Bake for another 15 minutes, or until the center barely jiggles when the pie is shaken gently. (The pie will set up more as it cools.)