Punnets of the freshly harvested seafood went on sale at 220 Tesco stores this week.
But rather than selecting seaweed from Swansea and Gower, as Harrods does, Tesco has cast its net across the English Channel. It has started importing up to 40 tonnes a week of rock-salted seaweed from the Brittany coast at Roscoff.
In South Wales and North Devon, where seaweed is one of the staples of the local diet, the foreign delicacy is likely to remain firmly on the shelves.
Tom Evans, a tourist officer in Barnstaple, Devon, and a connoisseur of the local plantlife, said: "I can't imagine a French variety selling here for one minute. It's a pity Tesco has had to go abroad. We wouldn't mind them using our laver so long as there's enough for us and the Canada Geese."
Elizabeth Williams, who runs Gower Coast Seafoods, in Crofty, and sells 500kg of laver each week, said: "They will not get anything better than we have got. It's ridiculous. We've got the quality and quantity."
Seaweed is a particularly rich source of iodine, minerals and vitamins and contains as much iron in an ounce as spinach does in over 6lb. It also contains proteins, carbohydrates, carotene and fibre. Mr Evans said: "If you eat it warmed for breakfast with bacon and an egg on top it keeps you going all day."
Tesco is stocking two varieties - sea lettuce and dulse, both recommended for an extra kick in dishes ranging from pasta and chicken to scrambled egg. It can be eaten raw or cooked but needs rinsing at least three timesto remove salt and sand.
Kelly Murphy, spokeswoman for Tesco, said: "At the time we were sourcing seaweed there was no British supplier who could supply the quantity and quality we wanted. But we are open to offers in this country.''Reuse content