In a mixing bowl, combine flour and salt, then cut in very cold butter until the mixture resembles coarse crumbs. Gradually add ice water, mixing until the dough comes together. Shape the dough into a disc, wrap it in plastic wrap, and refrigerate for 30 minutes to let it firm up.

On a lightly floured surface, roll out the chilled dough into a 12-inch circle. Carefully transfer the rolled dough to a pie plate, pressing it into the edges. Trim any excess dough and crimp the edges for a decorative look, then freeze the crust for 15 minutes.

In a medium saucepan, combine cranberries with water, sugar, lemon juice, and orange zest. Simmer over medium heat, stirring occasionally, until the cranberries burst and the mixture thickens, about 10–15 minutes. Allow to cool slightly.

In a mixing bowl, whisk together eggs, sugar, vanilla extract, flour, and nutmeg until smooth. Heat cream in a small saucepan until warm but not boiling. Gradually whisk the cream into the egg mixture, then pour this custard mixture over the cranberry filling in the pie crust.

Preheat your oven to 350°F (175°C). Bake the assembled pie for 45–55 minutes. The custard should be set but still slightly jiggly; the top will be golden. Cover edges with foil if they brown too quickly.

Let the pie cool completely on a wire rack for at least 2 hours, then refrigerate for at least 2 more hours before serving. Serve chilled, pairs wonderfully with whipped cream or vanilla ice cream.