Thinly slice the scallions, separating the whites and greens.
Cut the sushi-grade salmon into ½-inch cubes and place it in a bowl. Add the scallion whites, soy sauce, sesame oil, mayonnaise, sriracha, and optional masago or tobiko. Mix gently until everything is evenly coated, folding rather than stirring so the cubes stay intact.
Spoon the creamy salmon poke over a fresh bowl of warm rice.
Optionally garnish with the scallion greens and serve immediately.
