In a small bowl, mix the crème fraîche with the dill and season to taste with salt and pepper.
Peel the cucumber. Then, using the peeler, shave 16 wide strips from several sides of the cucumber (discard the seed core). In a medium bowl, toss the cucumber strips with 1/4 tsp. salt and let sit until softened, about 10 minutes. Pat dry with paper towels.
Spread the creme fraiche generously on one side of each bread triangle (you may not use it all). Top half of the triangles with a folded cucumber strip, a curl of the salmon, and a grind of black pepper. Set the remaining bread on top and serve.
Make Ahead Tips
You can combine the crème fraîche and dill, season to taste, and refrigerate this mixture for up to 1 day, tightly covered.
nutrition information (per serving):
Photo: Scott Phillips