Place the milk into a large saucepan. Heat on the hob on a moderate heat until it just starts to steam. Careful not to let the milk boil or burn on the bottom of the pan.
While the milk heats, place all of the other ingredients into a jug and mix thoroughly to form a smooth paste.
Once the milk is steaming, pour into the jug and mix quickly with the eggs and other ingredients. Pour back into the saucepan.
Return the saucepan to a moderate heat and slowly stir the custard using a whisk. The custard will start to thicken gradually - this will take 5-10 minutes. Resist the urge to turn the heat up high as this can cause the custard to split or burn on the bottom of the pan, and make sure you continue to stir with the whisk. Once the custard gently started to "blip" and bubble, the custard is ready!
Leave to stand for a minute, then serve!