Combine flour, cocoa powder, powdered sugar, butter, and egg yolk together in a food processor. Pulse together until a crumbly dough forms.
Wrap tightly in plastic wrap and chill for about 1 hour.
Roll it out on a lightly floured counter - the crust needs to fit a 12" x 4" tart pan. Preheat oven to 350°F.
With a fork, prick the crust all over. Cover with parchment paper and then fill with dry beans or pie weights. Bake in preheated oven for 15 minutes.
Remove from the oven, remove the dry beans or pie weights, and set aside to cool completely.
In a small saucepan add the half and half, butter and chocolate and stir over medium heat until the chocolate is melted and the ganache is smooth and silky.
Remove from the heat and stir in strawberry preserves.
Pour the filling into the baked tart crust and chill for few hours, or until set.
Decorate with grated chocolate, powder sugar or chocolate dipped strawberries.