What Christmas food is made from marsh-worts?

Marsh-worts are a type of plant, and while some plants are edible, marsh-worts are not typically used in food preparation. They are often considered poisonous.

It's possible you may be thinking of a different plant, or perhaps there's a misunderstanding about the name "marsh-wort."

Could you clarify what you're looking for? Maybe you can give me more details about the food or the plant you are thinking of.