Slice the cucumbers into rounds about 1/4 inch thick.
Slice the avocado and cut it into small slices, about the size of the cucumber.
Place the avocado slices on the cucumber rounds. Note: if you are making these ahead of time, squeeze a little lemon juice over the avocado to avoid browning.
Cut the smoked salmon into small pieces about twice as long as the cucumber. Fold the smoked salmon over and place on top of the avocado.
Sprinkle the black sesame seeds over the top. Serve and enjoy!