01 - Preheat oven to 350°F.
02 - Combine flour, cocoa powder, sugar, and salt in a mixing bowl. Cut in the cold butter using a pastry cutter until the mixture forms coarse crumbs.
03 - Add the egg yolk and 2 tablespoons of cold water. Mix until the dough comes together, adding up to 1 additional tablespoon of water if necessary.
04 - Shape the dough into a disk, wrap in plastic wrap, and refrigerate for 30 minutes.
05 - On a lightly floured surface, roll the dough to fit a 9-inch tart pan. Press into the pan, trim any excess dough, and prick the base with a fork.
06 - Line the crust with parchment paper and fill with baking weights or dried beans. Bake for 15 minutes. Remove parchment and weights, then bake an additional 10 to 12 minutes until firm. Allow to cool completely.
07 - Heat heavy cream in a saucepan over medium heat until just below boiling. Pour over the chopped chocolate in a bowl. Let sit for 1 minute, then add butter and stir gently until smooth and shiny.
08 - Pour the ganache into the cooled tart shell and smooth the surface. Chill in the refrigerator for at least 1 hour, until set.
09 - Place the halved strawberries over the set ganache in a decorative pattern.
10 - Warm the apricot jam and brush over the strawberries to create a glossy finish.
11 - Cut the tart into portions and serve chilled or at room temperature.