Shortening is any fat that is a solid at room temperature. Basically it is lard. In the UK Trex is a good one to use because it is soft and easy to spread. Some lards are quite hard and not easy to use. But any soft lard that is a solid is ok.
Great recipe, tempted to make them tomorrow. Can I use lard instead of the Trex? Lard and butter. Always wanted to try and make these but never had the guts!