150g butter, softened
75g caster sugar
1/2 tsp salt
125g plain (all-purpose) flour
50g rice flour
50g unsweetened (Dutch) cocoa powder
1 egg, lightly beaten
200g best-quality chocolate (72% cocoa solids)
190ml heavy cream
1 egg, lightly beaten
1. To make the tart shells, put the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment and beat until pale and creamy.
2. In a bowl, sift together the salt, flours and cocoa powder.
3. Using a spatula, fold the flours into the butter mixture until just coming together. Do not mix them using the electric mixer or you will overwork the dough and the tart base will shrink.
4. Tip the rough contents onto a work surface and using the heel of your hand, press down and away from you to spread the dough. Repeat three times.
5. Scrape the dough together into a ball and flatten. Wrap with plastic wrap. Refrigerate for 30 minutes.
6. Roll the dough into a circle about 5 mm (1/4 in) thick. Place a 22cm tart ring on the dough and run the tip of a knife around the inside of the ring. Remove any excess dough.
7. Place the tart bases on a baking tray and refrigerate for another 30 minutes.
8. Preheat the AEG 60cm SteamPro Steam Oven to 160°C. Bake the tart base in the oven for 10–12 minutes until the dough is dry. It will firm up once it cools.
9. Lightly beat the egg and use a pastry brush to paint a thin layer across the cooled bases. Return to the oven for 3 minutes to set the egg. This will prevent the base from going soggy once the filling is added.
10. To make the filling, chop the chocolate coarsely and place it in a medium heatproof bowl. Bring the cream and milk to the boil in a small saucepan on the AEG 90cm Induction Cooktop. Pour the hot milk mixture over the chocolate and stir until melted. Cool a little then whisk in the egg until fully incorporated.
11. Reduce the oven temperature to 100°C.
12. Pour the filling into the ring. Bake for 8–10 minutes until the filling is just set. It should still have a slight jiggle. Leave to firm at room temperature for 1 hour.
13. Serve, at room temperature within 2–3 hours, with whipped vanilla cream.