Let’s break down the process into easy-to-follow steps.

1. Make the Pie Dough:

• In a small bowl, whisk the egg, 4 tablespoons of ice water, and the vinegar until blended.
• In a large bowl, mix the flour and salt; cut in the lard until crumbly.
• Gradually add the egg mixture, tossing with a fork, until the dough holds together when pressed. If the mixture is too dry, slowly add additional ice water, 1 teaspoon at a time, just until the dough comes together.
• Divide the dough in half. Shape each into a disk; wrap and refrigerate for 1 hour or overnight.

2. Prepare the Filling:

• Preheat oven to 400°F (200°C).
• In a large bowl, mix the sugar and tapioca.
• Add the rhubarb and strawberries; toss to coat evenly.
• Let stand for 15 minutes. This allows the tapioca to start absorbing the fruit juices.

3. Assemble the Pie:

• On a lightly floured surface, roll half the dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim the crust even with the rim.
• Add the strawberry-rhubarb filling to the crust.
• Dot the filling with the butter.
• Roll the remaining dough to a 1/8-in.-thick circle. Place over the filling.
• Trim, seal, and flute the edge. Fluting creates a decorative edge and helps seal the filling inside.
• Cut slits in the top crust to allow steam to escape during baking.

4. Brush and Bake:

• Brush milk over the top crust.
• Sprinkle with coarse sugar.
• Place the pie on a baking sheet (to catch any drips).
• Bake for 20 minutes.

5. Reduce Temperature and Continue Baking: * Reduce the oven setting to 350°F (175°C). * Bake 45-55 minutes longer or until the crust is golden brown and the filling is bubbly.

6. Cool: * Cool the pie on a wire rack.

These are clear instructions.