Carageen is a type of seaweed found in Irish waters, particularly along the rocky Atlantic coasts. Apart from it being extremely healthy, it is also a great alternative to gelatin as when boiled it forms a jelly. A seaweed jelly may sound a bit odd but trust me, this is a truly unique and delicious little dessert. Recipe from The Pleasures of the Table: Rediscovering Theodora Fitzgibbon.