1. Make the crust: In a food processor, pulse the flour, butter, sugar, and salt until mixture resembles coarse crumbs. Add the egg yolk and 2 tablespoons of ice water, and pulse until the dough just begins to come together. Add the remaining 1 tablespoon of water if needed. Shape the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

2. Preheat the oven to 375°F. Roll out the dough on a lightly floured surface and press it into a 9-inch tart pan with a removable bottom. Trim any excess dough and prick the bottom with a fork. Bake for 15-18 minutes, until golden brown. Allow to cool completely.

3. Make the filling: In a medium saucepan, heat the cream over medium heat until simmering. Remove from heat and add the chopped chocolate. Whisk until the chocolate is melted and the mixture is smooth. In a separate bowl, whisk together the eggs, sugar, and salt. Slowly pour the egg mixture into the chocolate mixture, whisking constantly.

4. Pour the chocolate filling into the prepared tart crust. Bake for 20-25 minutes, until the center is set. Allow to cool completely before garnishing with gold leaf.