4 medium Persian or Japanese cucumbers, thinly sliced on diagonal (about 2 cups)
Butter lettuce
1 pound assorted smoked fish (such as salmon, trout, whitefish, sturgeon, and black cod)
Caper berries
Lemon wedges
Hard-boiled eggs, peeled, sliced (optional)
Directions
Mix first 3 ingredients in 2-cup glass measuring cup; gradually whisk in oil. Season with pepper. Pour half of mixture into small bowl; mix in 3 tablespoons sugar, capers, and shallot for sauce. Mix 1 tablespoon sugar into remaining mixture. Reserve for dressing salad.
Mix sliced fennel and cucumbers in large bowl. Mince enough fennel fronds to measure 3 tablespoons; add to bowl. Season to taste with dressing in measuring cup. Season with salt and pepper.
Cover large platter with lettuce leaves. Arrange smoked fish and salad atop lettuce. Garnish with caper berries, lemon wedges, and eggs (if desired). Serve with bread, butter, and Mustard-Caper Sauce.