01 - Preheat the oven to 350°F (175°C).
02 - In a mixing bowl, combine all-purpose flour, unsweetened cocoa powder, granulated sugar, and a pinch of salt.
03 - Cut in the cold, cubed unsalted butter until the mixture forms coarse crumbs.
04 - Add the egg yolk and two tablespoons of cold water. Mix until the dough comes together, adding an additional tablespoon of water if needed.
05 - Shape the dough into a disk, wrap in plastic wrap, and refrigerate for 30 minutes.
06 - On a lightly floured surface, roll the chilled dough to fit a 9-inch tart pan. Press into the pan, trim the excess, and prick the base with a fork.
07 - Line the tart shell with parchment paper and fill with baking weights or dried beans. Bake for 15 minutes. Remove weights and parchment, then bake for an additional 10–12 minutes until firm. Let crust cool completely.
08 - Heat heavy cream in a saucepan until just below boiling. Pour over chopped dark chocolate in a bowl and let sit for 1 minute. Add unsalted butter, then stir until the ganache is smooth and glossy.
09 - Pour the ganache into the cooled tart crust. Smooth the top with a spatula. Refrigerate for at least 1 hour until the ganache is set.
10 - Arrange the halved strawberries decoratively over the set ganache.
11 - If using, warm apricot jam and lightly brush over the strawberries to create a glossy finish.
12 - Slice and serve the tart chilled or at room temperature.