Preheat the oven to 400°. Using a sharp knife or mandoline, slice the potatoes lengthwise into 1/4" slices. Drizzle potato slices with olive oil and toss to coat with your hands. Place potato slices in a single layer on a baking sheet and bake for 10-12 minutes. Remove from oven and flip potatoes over. Return the baking sheet to the oven and cook for an additional 10-12 minutes or until potatoes are golden and crisp. Remove from oven and set aside.
Slice the smoked salmon into 1/2" wide slices. Top each potato round with a slice of smoked salmon, folding it over on itself to create some height.
Dollop the salmon with a scant teaspoon of creme fraiche and about 1/4 teaspoon of caviar. Garnish with a sprig of dill. Arrange on a platter and serve with champagne or cocktails.