In a small saucepan, bring the milk to a boil. Pour into a container, add the tea bags, cover and place in the fridge overnight to infuse. If you’re short of time, allow to infuse for at least an hour.
Remove the tea bags, squeezing out as much milk as possible, then pour the milk back into a saucepan and heat slowly.
Meanwhile, place the gelatine in a bowl of cold water and set aside.
In a medium-size bowl, whisk together the egg yolks, sugar and cornflour.
Pour half of the hot milk over the egg yolks, whisk quickly to combine then pour back into the saucepan. Whisk continuously until thick and bubbling. Once the first bubble appears, whisk for one minute more then remove from the heat.
Add the gelatine (discarding the water) and the butter. Whisk until smooth then cover and place in the fridge to cool.
Whilst cooling, whisk the cream until stiff peaks form.
Once cool, transfer into the bowl of your electric mixer and beat until smooth, add the cream and mix again until combined. Set aside.