1. Begin by roasting the rhubarb. Preheat oven to 230C fan-forced (250C conventional) and line a small baking pan with baking paper.

2. Rub vanilla seeds into the sugar in a medium bowl, then add the rhubarb pieces and toss together. Tip out onto the lined baking tray and roast for about 15 minutes until the rhubarb has softened. Remove from oven and set aside to cool.

3. Reduce oven temperature to 150C fan-forced (160C conventional). 

4. Place 6 ramekins (approx 10cm wide x 4cm deep) onto a baking tray and bring a kettle full of water to a boil.

5. Combine cream, milk, half of the sugar, ginger and vanilla pod (optional, reserved from making the rhubarb) in a medium pot and stir gently over low heat. When tiny bubbles begin to form around the edge of the pot, turn the heat off and allow the cream to infuse for 5-10 minutes.

6. Meanwhile, in a medium bowl, whisk together the yolks, whole egg, remaining half of the sugar and the salt until combined. Pour milk mixture into the egg mix, whisking continually as you do, then strain the custard base into a wide jug or bowl. Discard the ginger.

7. Strain the rhubarb (save the juice to make a refreshing drink topped with some sparkling water) and spread evenly on the base of the ramekins. Carefully pour about 125ml of the strained custard on top of the rhubarb, then place the pan with ramekins into the oven, making sure that the temperature has properly lowered to 150C fan-forced (160C conventional). Pour the just-boiled kettle of water into the pan, making sure it reaches halfway up the sides of the ramekins. Cover the pan with foil and bake the custards for about 45 minutes; the edges of the custard should be just set, while a small area in the centre will remain slightly wobbly. Remove from oven and allow to cool before refrigerating the custards for at least one hour or up to 2 days.

8. When ready to serve, sprinkle the caster sugar evenly over the surface of each custard. Using a blowtorch, caramelise the sugar to a deep golden brown by moving the blowtorch slowly over the entire surface. If you don't have a blowtorch, caramelise the sugar topping by placing the tray of custards under a preheated grill.*

*A blowtorch will help you achieve that ice-rink-thin toffee top, but if you don't have one, place the tray of custards under a preheated grill for a couple of minutes, watching them like a hawk to make sure they don't burn.

Failing a blowtorch or grill, you could also just dust the tops with icing sugar before serving, but know that it's the contrast between the crisp shell and gentle custard beneath that makes this dessert truly special.