Laver is an edible seaweed that has a high mineral salt content, particularly iodine and iron. It is used for making laverbread, a traditional Welsh dish, as well as eaten as a complement to rice in Japan (where it is called nori) and Korea (where it is called kim or gim). Particularly in Korea, it is sometimes roasted with sesame oil and further flavored with salt and sometimes MSG. Laver is common around the west coast of Britain and east coast of Ireland along the Irish Sea as well as along the coasts of Japan and Korea. Laver is unique among seaweeds because it is only one cell thick. It is smooth and fine, often clinging to rocks. The principal variety is purple laver (Porphyra laciniata/Porphyra umbilicalis). This tends to be a brownish colour, but boils down to a dark green pulp when prepared. The high iodine content gives the seaweed a distinctive flavour in common with olives and oysters.
Ulva lactuca, also known as Sea lettuce, is occasionally eaten as green laver, which is regarded as inferior to the purple laver.
Laverbread (Welsh: Bara Lafwr or Bara Lawr) is a traditional Welsh delicacy made from laver. To make laverbread, the seaweed is boiled for several hours then minced or pureed. The gelatinous paste that results can then be sold as it is, or rolled in oatmeal.
Laverbread is traditionally eaten fried with bacon and cockles for breakfast. It can also be used to make a sauce to accompany lamb, crab, monkfish, etc, and to make laver soup (Welsh: Cawl Lafwr).[9] Richard Burton has been attributed as describing laverbread as “Welshman’s caviar”.
Swansea Market has several stalls selling only laverbread and cockles from the nearby Gower Peninsula. The source of the seaweed used to make laverbread was historically the Gower coastline. There are still small producers of Gower laverbread, though it is now mainly along the Pembrokeshire coast.
Laver is often associated with Penclawdd and its cockles, being used traditionally in the Welsh diet and is still eaten widely across Wales in the form of laverbread. In addition to Wales, laverbread is eaten across the Bristol Channel in North Devon, especially around the Exmoor coast around Lynmouth and Combe Martin.
Laver is highly nutritious because of its high proportions of protein, iron, and especially iodine. It also contains high levels of vitamins B2, A, D and C.