Measure wheat berries and mill on a fine setting.
Add 1/2 tsp salt to flour and mix.
Cut in cold butter and lard until the mixture is coarse.
Add apple cider vinegar and mix.
Add ice-cold water one tablespoon at a time, mixing after each addition. Then, add enough water for the dough to come together into a cohesive ball. The amount will vary depending on your environment.
Cover and refrigerate for at least 30 minutes.
Preheat oven to 350°F.
Roll dough into an 11-inch circle. Do not add extra flour. If the dough begins to stick, place parchment paper or plastic wrap over the top and roll it out that way. Otherwise, adding flour can create a gritty texture.
Grease a 9-inch pie plate with butter and fit dough into the pan, fluting the edges.
Pierce the bottom with a fork.
Line with parchment and add pie weights to prevent bubbling.
Par-bake for 15 minutes.
Carefully remove weights and bake an additional 10 minutes, until lightly golden.
Allow the crust to cool completely.
While the crust cools, whisk eggs and heavy cream until fully combined. If desired, add salt to taste.
Add 1 cup of your custom ingredients to each crust (pre-cooked as needed).
Pour the egg mixture over the filling.
Bake at 350°F for 35–40 minutes, until the internal temperature reaches 165–185°F.