Continue to cook, whisking constantly, until the custard has reached your desired thickness – this usually takes about 10 minutes but will depend on how runny you want your custard to be. You must whisk the custard constantly to avoid it going lumpy.
08Remove from the heat and continue to whisk for another minute.
09Serve.
10If you’re making the custard to use later: Put the custard into a bowl or jug and cover with cling film. It is important that the top of the custard is in full contact with the cling film to prevent a skin forming while the custard cools.
11Place into the fridge until you’re ready to use it.
12When you want to use the custard, reheat in a pan, stirring regularly to ensure that a skin doesn’t form. You’ll find that the custard will thicken further as it reheats. It it starts to become too thick, simply add a little more milk to get it to your desired consistency.