In a food processor, pulse together 2 1/2 cups of all-purpose flour and a teaspoon of salt until combined. Add 1 cup of chilled unsalted butter and 1/2 cup of lard, pulsing until the mixture resembles coarse crumbs. Gradually add 6 to 8 tablespoons of ice-cold water, mixing until the dough forms. Divide the dough into two disks, wrap them in plastic wrap, and refrigerate for at least 30 minutes to firm up.

While the dough chills, hull and slice 2 cups of strawberries, and trim and cut 2 cups of rhubarb into ½-inch pieces. In a large mixing bowl, combine the strawberries, rhubarb, 1 cup of sugar, 1/4 cup of cornstarch, and a pinch of salt. Let this mixture sit for about 15 minutes to allow the fruit to release its juices.

Preheat your oven to 375°F (190°C). Roll out one disk of the chilled dough on a floured surface to fit your 9-inch pie plate. Carefully transfer the rolled dough to the pie plate, pressing it gently into the bottom and sides. Pour in the filling and spread it evenly. Roll out the second dough disk and place it over the filling; pinch the edges to seal, and cut slits in the top crust to allow steam to escape.

Once assembled, bake the pie in your preheated oven for approximately 1 hour and 30 minutes. Look for a golden brown crust and bubbling filling as indicators of doneness. If the edges brown too quickly, shield them with foil.

After baking, remove the pie from the oven and allow it to cool on a wire rack for at least 5 hours before slicing. This cooling time will help the filling set properly.