Mix in a food processor the flour, sugar, and salt.
Add the butter, cutting it into small pieces or pulsing until it resembles coarse crumbs.
Beat the water and egg yolk until homogeneous and add just enough to form the dough into a ball (you may need a little more or less liquid depending on the humidity in the air).
Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.

Preheat the oven to 350°F (180°C).

Roll out the dough on a floured surface and place it in a 9-inch (23cm) tart mold.
Poke the bottom of the tart with a fork, line it with parchment paper, and fill with pie weights.
Place the tart mold on a baking sheet and bake for 15 minutes, then remove the weights and return the mold to the oven for 8 minutes, or until the dough is pale and dry, but not cooked. Let cool.

Increase the oven temperature to 400°F (200°C).

Place the walnuts and 2 tablespoons of sugar in a food processor and chop finely in pulse mode.

Mix the butter and remaining sugar in a bowl until light and fluffy.
Add the walnut mixture and mix until homogeneous.
Add the egg yolks to the mixture and mix until well combined.
Add the flour.
Pour the walnut cream into the tart shell and spread evenly.

Cut the figs into quarters, but do not cut through the base.
Arrange the figs on the tart, leaving them slightly open like flowers, but not too spaced out.

Place the tart on a baking sheet in the lower third of the oven and bake for 40-45 minutes, or until the walnut cream has puffed and is lightly browned.

Warm the apricot jam in the microwave or in a small saucepan over low heat until liquid.
Brush the figs with the glaze using a pastry brush.