In Sweden, raksmorgas, toasted bread topped with mayonnaise and piled high with shrimp, is a popular snack. Here, it’s miniaturized into a cocktail-size bite with zippy horseradish butter as the base with shrimp, hard-cooked egg, cucumber, arugula, and dill. You can buy thinly sliced, dense rye or pumpernickel bread in a brick-shape loaf at many specialty markets; Mestemacher is one popular brand. Be sure the jar of horseradish is fresh; the flavor deteriorates within a few weeks after opening. Buy shrimp already cooked and this hors d’oeuvre comes together quickly.
|½||cup (1 stick) unsalted butter, at room temperature|
|2||tablespoons drained prepared white horseradish in brine, or more to taste|
|1||teaspoon Dijon mustard|
|1||teaspoon finely grated lemon rind|
|1||tablespoon lemon juice|
|Salt and pepper, to taste|
|8||slices dense rye or pumpernickel bread|
|½||English cucumber, thinly sliced|
|1||handful fresh arugula|
|24||large cooked, peeled shrimp (about 1¼ pounds) sliced in half lengthwise|
|3||sprigs fresh dill, snipped with scissors|
|¼||cup capers, drained|
|Lemon wedges (for serving)|
1. Bring a saucepan of water to a boil. Add the eggs and cook them for exactly 10 minutes. Transfer to cold water and crack the shells with the back of a spoon. Remove a strip of shell and let the cold water run until the eggs are cold. Peel them, dry on paper towels, and slice.
2. In a small bowl, mash together the butter, horseradish, mustard, lemon rind, lemon juice, salt, and pepper. Taste for seasoning and add more horseradish, if you like.
3. Set the bread on a cutting board and spread each slice with about 1 tablespoon of the butter. Top with cucumber and arugula. Place 3 egg slices in a line on top, and set 2 shrimp halves on each slice of egg. Cut each slice of bread into 3 pieces and garnish with capers and dill. Serve with lemon.