Mini Blueberry Tarts

Tart shells (can be made one day in advance):

1. Dough: Place the flour, icing sugar, lemon zest, salt, and butter in the food processor and process until you get a coarse mixture that resembles breadcrumbs; you should still have some small butter pieces visible.165 g all-purpose flour/ 6 oz/ 1 ⅓ cups + 50 g icing sugar/ ½ cup + ¼ teaspoon lemon zest + 1 pinch of salt + 90 g unsalted butter/ 3.2 oz/ ⅓ cup + 1 tablespoon
2. Add the yolk and the ½ tablespoon water and mix briefly until the dough comes together. Only add more water if necessary; the pastry should hold together when you pinch it.1 small egg yolk + water
3. Refrigerate: Turn the pastry onto the working surface and knead lightly to form a smooth disc for just a few seconds to form a smooth disc. Divide the pastry into two portions, wrap each piece in plastic foil, and refrigerate until needed. It will keep for a week in the fridge and a month in the freezer.
4. Prepare muffin tin: Brush the muffin tin with melted butter, place it in the fridge, and leave to set for about 30 minutes.
5. Form: Dust the working surface with very little flour. Take one portion of the wrapped pastry out of the fridge and divide it into 6 pieces. Form 6 small balls and roll each one into a circle, about 2-3 mm/ 0.07 - 0.10 inches thick and large enough to cover the bottom and the walls of the muffin tin. Repeat with the second portion of pastry.
6. Blind bake: Preheat the oven to 150°C/ 300°F. Line each pastry shell with a paper muffin case, fill with dry beans or rice, and bake blind for about 25 minutes. Remove the beans/rice and the paper. The cases should be golden-brown. If they are not so yet, bake for another 5 to 10 minutes without beans and paper.
7. Cool: Let the shells cool slightly, about 5 minutes, and remove them from the muffin tin while still warm; they will slide out of the form. Place on a wire rack to cool completely, then fill.

Blueberry Curd (should be made one day in advance):

1. Cook: Place the blueberries, sugar, and lemon juice in a small saucepan. Bring to a boil, stirring occasionally. Turn the heat down and simmer for about 5 minutes. Remove from the heat, let cool down for about 10 minutes, and blend with an immersion blender. Place on the stove again and bring it to a simmer.400 g blueberries/ 14 oz + 150 g granulated sugar/ ¾ cup + 60 ml freshly squeezed lemon juice/ ¼ cup
2. Cornstarch slurry: In the meantime, whisk the cornstarch, egg yolks, and 1 or 2 tablespoons of water to obtain a paste. Stir this paste into the blueberry mixture in a thin stream and let bubble gently for 1 minute while whisking constantly.2 tablespoons cornstarch + 2 large egg yolks + 1-2 tablespoons water
3. Remove from the heat and stir in the butter and the salt. Allow to cool slightly, transfer to jars, and, once cooled completely, keep refrigerated.2 tablespoons unsalted butter + 1 pinch of salt

Meringue:

1. Beat the egg whites: Place the egg whites into a clean bowl and whisk with an electric mixer until quite stiff. Slowly and gradually, start adding the sugar and continue beating the eggs until the mixture becomes stiff and glossy.250 g granulated sugar/ 1 ¼ cup + 4 egg whites

Assemble and finish the blueberry tartlets:

1. Preheat the oven to 180°C/ 350°F.
2. Fill the tart shells ¾ full with blueberry curd and pipe or spoon some meringue on top.
3. Bake: Place the tarts on a baking tray and bake in the oven for about 3 to 5 minutes until the meringue top is slightly golden. Keep an eye on them while in the oven; the time the meringue needs to get slightly golden depends on your oven.