Samphire is a sea vegetable that grows abundantly on shorelines, in marshy shallows and on salty mudflats. It has a crisp texture and tastes of the sea.
Good fishmongers will sell samphire. Otherwise, try looking for it at your local farmers' market.
Wash samphire thoroughly under running water before use. Don't add salt to the cooking water as it's already salty enough. Use fresh in salads or serve it boiled and dipped in melted butter to be eaten like asparagus with fish dishes.