Preheat your oven to 375°F (190°C). Line a 15x10x1 inch baking pan with parchment paper to prevent the pastry from sticking and to make cleanup easier.

Take 1 ½ discs of the homemade pie dough (butter-lard blend) and roll them out together into a 12x18 inch rectangle. Carefully transfer this rolled dough to the prepared pan, allowing the pastry to hang over the sides of the pan. This will become the base and edges of your slab pie.

Using the remaining 1 ½ discs of homemade pie dough, roll them into an 11x16 inch rectangle. Set this piece aside—it will be used to cover the filling after it's added.

Pour the homemade sour cherry filling into the prepared bottom crust in the pan. Sprinkle the grated lemon peel evenly over the cherry filling. Then gently place the prepared top crust from Step 3 over the filling. Bring the overhanging edges of the bottom crust up over the top crust, pinching to seal and flute the edges for a decorative look. I like to give the edges an extra press with my fingers to make sure they're really sealed and golden once baked!

Brush the top crust evenly with heavy cream, or use an egg wash made by blending 1 large egg with 1 tablespoon of water. Sprinkle generously with coarse Demerara sugar for a crunchy, sparkly finish. Using a fork, dock the top crust by poking small holes or vents; this allows steam to escape during baking.

Place the assembled slab pie on the middle rack of the oven and bake for 50 to 55 minutes, or until the crust is deeply golden and the cherry filling is bubbling. This ensures the pastry is cooked through and the filling is perfectly thickened.

Transfer the baked pie to a wire rack and let it cool until just warm, about 40 minutes. This helps the filling set so you get clean slices. Once cooled, slice and serve. I always find the pie is easiest to cut and most delicious when it's still a bit warm from the oven!