1/2tspAmerican yellow mustard – I always use French's Classic Yellow Mustard– sweet mustard also works
1/2tspsugar
Salt and pepper
Pickled mustard seeds for the top (optional)
Dill and watercress
Instructions
Stir the crème fraîche and mayonnaise together with the sugar, shallot and all three kinds of mustard. Season to taste with salt and pepper.
Pat the herring fillets dry with a little kitchen paper and cut them into smaller pieces.
Fold the herring pieces into the dressing and chill until ready to serve.Just before serving, top the herring with dill and watercress and, if using, pickled mustard seeds.