This a very quick recipe to make a delicious custard
20 grams of sifted flour
250 ml of milk (I use skimmed milk, but feel free to use full fat)
60 grams of caster sugar
A table spoon of icing sugar
Separate the yolks from the whites, add 40 grams of sugar and whisk at max speed until you reach a ribbon like consistency.
When they are done (this can take up to 10 minutes), reduce the speed and add the sifted flour.
In the meantime, add the remaining 20 grams of sugar to the milk and bring it to the boil.
(You can split a vanilla pod and add the seeds to it, to give it more flavor. If doing so, add also the pod and leave it to infuse for 10 minutes. After 10 minutes, pass through a fine sieve, and bring it back to boil)
As soon as it starts bubbling up, take off the heat and slowly add it to the eggs, keep whisking.
Bring everything back to the pan, and heat for 3-5 minutes, until it thickens up.
Transfer to a bowl, dust with icing sugar (to prevent the thin crust forming), and leave it to cool before putting it in the fridge.