Sweet tart pastry
Whisk together yolk, cream and vanilla in a small bowl. Combine flour, cocoa, sugar and salt. Rub in butter.
Add cream mixture untill dough forms. Make into 6 inch disk and refridgerate for 1hr up to 48 hrs.
Bake 30 mins at 375 deg F plus five mins without foil. Cool for thirty mins.

Filling
Cream and milk at med/low until just starts to simmer. Stir in chocolate, sugar and salt and let stand for 5 mins. Whisk eggs until blended. Stir in and whisk until blended.

Bake 325 deg F 15 to 20 mins in the cooled shell. If bubbles or cracks on surface pull out. Cool before cutting, serve warm.