Prepare the Sweet Pastry (Pâte Sucrée) Shells

Cup of Yum
1. In a stand mixer fitted with a paddle attachment, cream the softened butter and sugar on medium speed for about 2 minutes, until pale and creamy.
2. Scrape down the sides and bottom of the bowl with a rubber spatula, and mix for another 20 seconds.
3. Add the egg, vanilla paste, salt and lemon zest, and beat on low speed until the yolk is evenly incorporated and the mixture is clumpy, for about 30 seconds.
4. Add the flour and mix on low speed for about a minute, until the flour is incorporated. The mixture will look like wet, clumpy sand.
5. Using your hand, lightly knead the dough into a ball inside the bowl. You can transfer the dough to your worktop to knead it if easier, but make sure not to overwork the pastry.
6. Turn the dough into a ball and then roll between two sheets of baking paper, about 3 mm (⅛") thick.
7. Place on a flat tray and leave to rest in the fridge for at least an hour.
8. Take the dough out of the fridge, remove the baking paper and cut out 10 rounds of pastry using a small knife. You can also use a round or fluted cookie cutter.
9. Gently slide the pastries into the small tart tins, lightly pressing the edge between the bottom and the sides to remove any air bubbles.
10. Prick the bottom of the pastries with a fork to avoid them rising, then place them back in the fridge to rest for another hour.
11. Preheat your oven to 170° C (340° F) and place the tart tins in the freezer in the meantime.
12. Line each tartlet shell with a small piece of cling film or baking paper and cover with baking beads, beans or chickpeas.
13. Bake the shells for 10-12 minutes, remove the baking weights and cling film carefully, then bake for another 15 minutes or until golden brown.
14. Leave them to cool down completely before adding the filling.
15. Proceed to prepare the chocolate ganache while the pastry shells are cooling down.

Prepare the Chocolate Ganache

1. Chop the dark chocolate and milk chocolate into small pieces and place them in a bowl.
2. Heat the cream in a small saucepan until simmering (not boiling), and pour it into the chopped chocolate. The cream doesn't need to boil fully, but you should see some steam coming out of the pan.
3. Leave the chocolate and cream without stirring for about one minute. Using a spatula, stir them until the chocolate melts in the cream, and emulsifies into a smooth ganache.
4. Let the ganache cool down just a little (for a few minutes), and pour it over the tartlet shells. Use a small spatula (or the back of a spoon) to spread it evenly if necessary.
5. Place the tartlets in the fridge to set for about an hour - or until the ganache has hardened before decorating with strawberries, nuts or any topping you like.