01 - Set oven temperature to 350°F (175°C) to allow adequate preheating before baking the crust.
02 - In a mixing bowl, combine all-purpose flour, cocoa powder, granulated sugar, and a pinch of salt.
03 - Cut cold, cubed unsalted butter into the dry ingredients using a pastry cutter or fork until the mixture forms coarse crumbs.
04 - Blend in egg yolk and two tablespoons of cold water. Mix together until the dough comes together, adding an additional tablespoon of water if necessary.
05 - Shape the dough into a disk, wrap in plastic wrap, and refrigerate for 30 minutes to relax the gluten and firm the dough.
06 - On a lightly floured surface, roll out the dough to fit a 9-inch tart pan. Gently press it into the pan, trim any overhang, and prick the base with a fork.
07 - Line the pastry shell with parchment paper and fill with baking weights or dried beans. Bake for 15 minutes, then remove the weights and parchment. Return the shell to the oven and bake an additional 10 to 12 minutes until firm. Allow crust to cool completely on a wire rack.
08 - Heat heavy cream in a saucepan over medium heat until just below boiling. Pour over finely chopped dark chocolate in a heatproof bowl and let stand 1 minute. Add unsalted butter and stir gently until the chocolate mixture is smooth and glossy.
09 - Pour the ganache into the cooled tart shell and smooth the surface. Refrigerate for at least 1 hour until the ganache is fully set.
10 - Arrange the halved fresh strawberries evenly across the surface of the set ganache.
11 - If desired, gently warm apricot jam and use a pastry brush to glaze the strawberries for a glossy finish.
12 - Slice the tart with a sharp knife and serve chilled or at room temperature.