Use a little more cornflour if you like your custard thick. Put the egg yolks in a medium saucepan with the cornflour and sugar. Scrape the vanilla seeds into the pan, or add the vanilla extract ...
Cut the vanilla pod open lengthways and scrape out ... whisking as you go. Transfer the custard to a clean pan, and set it over a very low heat. Stir the custard constantly with a wooden spoon ...