Cream Puffs

Crème Pâtissière Filling:

Pour the milk and vanilla seeds into a heavy-based pan and bring gradually to a boil. Remove from the heat.
In a medium bowl, whisk together the egg yolks and caster sugar until pale, then whisk in the cornstarch and flour. Pour the vanilla-infused milk onto the eggs, whisking continuously, then pour back into the pan.
Bring back to a boil, whisking continuously over medium heat and cook for one minute.
Pour the crème pâtissière into a bowl. Cover the surface with cling film to prevent a skin from forming, and leave to cool. Transfer to the fridge to chill.

Preheat the oven to 425℉, convection. Line a baking tray with baking parchment and draw onto it 12 circles 5cm/2in wide.
Put the butter in a heavy-based saucepan with 150ml/5fl oz of water and heat over medium heat until the butter melts. Bring the mixture to a boil and then immediately remove from the heat.
Quickly tip in the flour. Stir vigorously with a wooden spoon until the mixture forms a soft ball. Return to the heat and cook over a low heat for 3-5 minutes, stirring constantly.
Remove from the heat and leave to cool slightly. Gradually add the eggs, beating well between each addition to form a smooth, shiny paste.
Spoon the mixture into a piping bag fitted with a 1.5 cm / .5 in plain nozzle. Pipe round discs onto the baking tray in the marked circles and, using a damp finger, smooth over the top of each disc.
Bake in the center of the oven for 10 minutes. Reduce the oven temperature to 375℉ and bake for another 10-15 minutes. Remove the choux buns from the oven and pierce each bun with a skewer to allow the steam to escape. Return to the oven for 4-5 minutes to dry out. Remove from the oven and leave to cool on a wire rack.

Bring the cream to a boil in a small pan. Remove from the heat.
Add the chocolate and stir until melted and shiny.
Transfer to a bowl and leave to cool, then chill in fridge until thickened to a spreadable consistency.

Spoon the cold crème pâtissière into a piping bag fitted with a long thin nozzle. Fill the choux buns with the crème pâtissière.
Dip the filled buns into the chocolate ganache to coat half-way up the sides.