Preheat the oven to 400°F. Line a baking sheet with parchment paper.
Place the salmon fillets on the prepared baking sheet. Season with salt and pepper, then brush with teriyaki sauce.
Bake the salmon for 12-15 minutes or until cooked through and flakes easily with a fork.
While the salmon is baking, prepare the rice by fluffing it with a fork.
In a large bowl, combine the cooked rice with olive oil and a pinch of salt. Mix well.
Once the salmon is done, remove it from the oven and let it cool slightly. Flake the salmon into bite-sized pieces.
To assemble the stacks, use a round mold or a small bowl. Start with a layer of rice at the bottom, followed by a layer of flaked salmon, then a layer of avocado slices, and finally a layer of cucumber.
Carefully remove the mold and repeat the stacking process for the remaining ingredients.
Garnish each stack with chopped green onions and a sprinkle of sesame seeds.