Preheat the oven to 140C/285F/Gas 1
For the crème brûlées, lightly butter 12 very small ramekins.
Place the sugar and egg yolks into a bowl and whisk together.
Place the milk and cream into a pan over a low heat and bring to the boil.
Gradually pour the hot milk and cream mixture onto the eggs, whisking constantly to combine.
Place the chocolate into a clean bowl. Pour a third of the custard onto the chocolate and whisk well until all the chocolate has melted.
Strain the chocolate custard into four of the ramekins.
Pour half of the remaining custard into a clean bowl. Add the lemon zest and juice, stir to combine, then pour into four of the clean ramekins.
Add the mint and peppermint essence to the remaining custard and leave to infuse for five minutes. Place a stick blender into the mint-infused custard and blend to combine.
Pass through a sieve and pour into the remaining four clean ramekins.
Place the ramekins into a roasting tray. Pour water into the roasting tray to half-fill with water, then transfer to the oven to bake for 30 minutes, or until the custards are just set.
Remove the crème brûlées from the oven and the roasting tin. Leave to cool, then place into the fridge to chill.
For the palmiers, preheat the oven to 200C/400F/Gas 6.
On a clean flat surface, roll the puff pastry out to ½cm/¼in thick.
Sprinkle with three-quarters of the caster sugar and three-quarters of the grated nutmeg.
Starting at one end of the pastry, roll the pastry up towards the middle of the pastry.
Turn the pastry around and roll the other side up towards the middle to leave two even rolls of pastry meeting in the middle.
Cut the rolled up pastry into 1cm/½ thick slices. Place each slice flat onto a work surface and flatten out slightly with a rolling pin.
Place the pastry pieces onto a baking sheet and dust with the remaining sugar and nutmeg.
Transfer to the oven and bake for 12-15 minutes, until golden and crisp. Remove from the oven and allow to cool.
To serve, when the crème brûlées are cold and fully set, slide a knife gently around the edge of each of the custards and turn each onto a large serving plate.
Place one third of the demerara sugar into a clean bowl with a little drop of the peppermint essence. Sprinkle on top of the mint crème brûlées.
Top the lemon and chocolate brûlées with the remaining demerara sugar.
Using a mini-blowtorch, heat the sugar topping of each crème brûlée, until the sugar melts and caramelises.
When the caramel has cooled, garnish each mint crème brûlée with a sprig of mint; garnish the lemon crème brûlées with a twist of lemon peel; and garnish the chocolate crème brûlées with some shards of chocolate.
Add several palmiers to the plate and serve.
