In a large bowl, place the lard and butter. Add the flour and salt and rub together with fingers to form small balls. Add the cold water, 1 tablespoon at a time, mixing the flour mixture in between each tablespoon. Only add enough water until dough comes together in one large ball.
Spread some flour on a piece of waxed paper and place the dough on it. Sprinkle some more flour on top of the dough and proceed to roll out the dough until desired thickness, about 1/8 inch thick. Fold the dough over once to make a half moon and again to make it a quarter moon. Remove the dough from the waxed paper and place into a (9-inch) pie pan. Unfold the dough so that it covers the entire pan. Press dough gently into pan. Using a fork, crimp the edges of the dough along the edge of the pie pan and cut away excess dough with a pairing knife. Set the pie shell aside.
Preheat the oven to 325 degrees F. In a bowl, combine the corn syrup, sugar, butter, vanilla, and eggs. Mix with a whisk until well incorporated. Place the pecans in the pie shell and pour mixture over nuts. Be careful not to overflow the shell. Bake the pie for 45 minutes. The pie should be firm and golden brown. Let pie cool before cutting. Pie may be garnished with whipped cream, nuts and mint.