In a large mixing bowl, whisk together all-purpose flour and a pinch of salt. Cut in cold butter until the mixture resembles coarse crumbs. Gradually add ice water, mixing gently until just combined. Shape the dough into a disc, wrap it in plastic, and chill in the refrigerator for 30 minutes.

On a floured surface, roll out the chilled dough into a 12-inch circle. Carefully transfer the rolled dough into a pie plate, trimming any excess. Crimp the edges and place the crust in the freezer for 15 minutes.

In a medium saucepan, combine cranberries, water, sugar, lemon juice, and orange zest. Bring to a boil, then reduce heat and simmer for about 10-15 minutes until the cranberries burst. Allow to cool slightly.

In a mixing bowl, whisk together eggs, sugar, vanilla extract, flour, and nutmeg until smooth. Heat heavy cream until just boiling, then gradually whisk it into the egg mixture.

Preheat oven to 350°F (175°C). Spoon craanberry filling into the chilled pie crust, then pour custard mixture over it. Bake for 45-55 minutes until custard is set with a slight jiggle in the center.

Once baked, cool completely on a wire rack. Refrigerate for at least 2 hours before serving. Slice and enjoy.