Meantime chocolate porter 50ml (open a while before you make the drink so it doesn’t fizz over when you shake it)
dark rum 35ml
sugar syrup 15ml
nutmeg grated to serve
To serve cold, put all of the ingredients (except the nutmeg) into a shaker and shake well without ice to mix and aerate the egg. Open the shaker, fill with ice and shake hard again for around 10-15 seconds. Strain into a glass with a few ice cubes, if you like, and grate some nutmeg over the top.
To serve hot, put all of the ingredients (except the nutmeg) into a pan and heat gently, whisking everything together until it’s warmed through – don’t let it get too hot or the egg will scramble. Pour into a glass and grate some nutmeg over the top.