Dice the smoked salmon into bite-sized pieces, slice the avocado and cucumber, and chop the scallions thinly.

In a small bowl, combine soy sauce, sesame oil, and Sriracha until well mixed.

Assemble each bite by placing a cucumber slice as the base, topping it with smoked salmon pieces, avocado slices, and scallions. Drizzle with the prepared sauce.

Arrange on a platter and garnish with sesame seeds or cilantro if desired.

Serve immediately or keep chilled until ready to enjoy.