The odd name is an anglicized mishearing of 'salmagundi,' an old English mixed-pickle dish, garbled by generations of Nova Scotian fishing families.
Salted herring fillets are soaked, then pickled in vinegar, sugar, onion, and sour cream, and sold cold in jars from market stalls as a spread for crackers. It's a fixture at Nova Scotia farmers' markets, especially around the holidays.
Japadog