Preheat oven to 325°F.
Wrap flatbreads in foil packet and place in oven to warm.
In a small bowl, stir together sour cream, lemon juice and lemon zest, until smooth. Season to taste with
salt and pepper. Set aside.
Using a vegetable peeler, slice cucumber end-to-end into long strips, rotating cucumber after every few passes to keep strips even. Discard core.
Place chopped avocado in a bowl with olive oil and mash with a fork until spreadable, but still slightly chunky. Season to taste with salt and pepper.
Remove flatbreads from foil pack and place on individual plates.
Spread approximately one quarter of mashed avocado onto first flatbread; repeat with remaining flatbreads.
Top each portion of mashed avocado with 1 ounce salmon and 1-2 egg slices.
Drizzle with lemon cream. Add 2-3 cucumber strips to each flatbread, then sprinkle with red onion and capers.
Scatter with dill sprigs and finish with a small dollop of salmon roe (optional).