Put the cream, milk and cardamom seeds in a saucepan. Heat until steaming then remove from the heat, pop a lid on the pan and set aside for 20 mins for the flavours to infuse.
Whisk the egg yolks with the sugar then whisk in the flour. Pour in a little of the warmed milk mixing well to incorporate then gradually whisk in the remaining liquid.
Rinse out the pan, then sieve the milk mixture back in to remove the cardamom pods. Cook over a low to medium heat, stirring near constantly for 4-5 mins until you have thick custard that coats the back of a spoon. Pour over your favourite pud, or eat the whole lot with a spoon.