Preheat the oven to 150 ?C. In a large saucepan, bring to the boil the lemon verbena leaves, cream, milk and vanilla pod. Remove from the heat and allow to infuse for 15 minutes.
Whisk egg yolks and castor sugar together until pale, think and glossy. Pour the infused milk into the yolk mixture and gently whisk. Strain into a large jug through a fine sieve. With a spoon remove any excess froth.
Pour into ramekins and place each into the bain marie. Cook for 40-50 minutes or until the custards have set. This can be checked by placing a knife into the centre of the custard and ensuring it comes out clean. Remove and cool completely before placing in the fridge.
When ready to serve scatter evenly the demerara sugar over each brulee and blowtorch until golden.
Notes & Tips
TIP: If you don't have a blowtorch, you can place them under a hot grill for less than a minute to burn the sugar