For mustard sauce: Whisk together oil, mustard, honey, vinegar and dried dill weed.Advertisement
Build sandwiches by spreading bread with butter, then layering cucumber, gravlax, egg, mustard sauce, capers, onion and fresh dill weed. (Extra sauce keeps well in the refrigerator.)
Gravlax is a type of cured salmon that’s hard to find in stores, but if you’re in the mood for a kitchen adventure, recipes to make it yourself abound online. Lox is a readily available substitute.