Boil fingerling potatoes until fork-tender, about 15 minutes. (At this point you can place potatoes in a warming tray or low-temperature oven to keep warm until your guests arrive.)
Mix together the creme fraîche, herbs, and capers in a small bowl.
To assemble, cut each potato in half and place 4 halves on a salad plate.
Top each potato with a spoon full of the creme fraîche mixture.
Take a piece of smoked salmon (or shrimp), fold it in half and put on top of potato and creme fraîche.
Top with a sprig of dill.
Serve warm.
