The number of coeliac customers who come to the restaurant always amazes me. I have my good friend Noleen Boyle, a wonderful pastry chef from Donegal, to thank for this recipe and we always make sure that we have some available for anyone who requests it. Supermarkets are getting much better at stocking gluten-free products, so you should be able to get the tritamyl flour and rice bran from their specialist section. Otherwise, any health food shop should ha