For the tempura, place the vegetable oil into a deep, heavy-bottomed saucepan and heat until a small cube of bread sizzles and turns golden when dropped into it. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Place half of the flour, cornflour and salt into a bowl and gradually stir in enough ginger ale to make a batter. Don't over-mix - it doesn't matter if a few lumps remain.
Dip the figs into the batter to coat completely. Place into the hot oil and deep fry until golden-brown and crisp. Remove from the pan with a slotted spoon and drain on kitchen paper.
Place the remaining flour, cornflour and salt into another bowl and gradually stir in enough sparkling water to form a batter.
Dip the strawberries into the batter to coat completely. Place into the hot oil and deep fry until golden-brown and crisp. Remove from the pan with a slotted spoon and drain on kitchen paper.
Preheat the oven to 150C/300F/Gas 2.
For the crème brûlée, place the milk into a saucepan, add the lemon verbena and bring to the boil. Remove from the heat and allow to cool and infuse for a few minutes.
Place the egg yolks into a large bowl with the sugar and whisk until combined.
Pour the milk mixture into the bowl along with the cream and whisk thoroughly.
Place four ramekins into a roasting tin and pass the cream mixture through a sieve into the ramekins. Pour in enough boiling water to come halfway up the sides of the ramekins.
Transfer to the oven and bake for an hour, or until just set. Remove the ramekins from the tin and allow to cool.
Once cooled, place the ramekins into the freezer until the custards are solid.
Use a knife to loosen around the edges of the ramekins and carefully tip the custards out of their ramekins onto a board. Using a pastry cutter, cut out a circle from each custard to make cylinders slightly smaller in diameter than the ramekins. Place onto serving plates and leave to soften for five minutes.
For the strawberry sauce, place the strawberries and icing sugar into a small food processor and blend until smooth. Pass the mixture through a sieve into a bowl to remove the seeds. Taste to check the sweetness and add more sugar if necessary.
To serve, sprinkle the demerara sugar over the top of the crème brûlées and caramelise with a mini-blowtorch. Place two fig halves and three strawberries onto each plate and drizzle over the strawberry sauce.