Xanthan gum is the magic ingredient that makes gluten free baking give more reliable results.
You can buy it in most Irish supermarkets now, either bunged in with the “special diet” foods or somewhere in the baking section. It is also available to order online from Eco Direct, who are marvellous.
I use the Doves Farm brand but as long as it’s gluten free I don’t think it really makes much difference.
Xanthan gum is really handy for baking where it provides the elasticity that is missing without gluten. I find it makes pastry much easier to handle and improves the crumb structure in cake.