Rinse the sushi rice under cold water until the water runs clear.
Cook the sushi rice using a rice cooker or a pot with 2 ½ cups of water.
Once cooked, let the rice cool slightly before adding rice vinegar.
Preheat the oven to 375°F (190°C) while preparing the salmon.
Season the salmon fillet with soy sauce, then sear it in a hot skillet for about 3-4 minutes on each side until cooked through.
Flake the cooked salmon and set it aside to cool slightly.
In a bowl, combine mayonnaise, sriracha, and diced avocado, mixing well.
Layer the sushi rice into a greased baking dish, pressing it down firmly.
Spread the flaked salmon evenly over the rice layer.
Top the salmon with the mayonnaise mixture, spreading it to cover completely.
Sprinkle with chopped green onions and pieces of nori.
Bake in the preheated oven for 20-25 minutes, until heated through and slightly golden on top.
Remove from the oven and let it cool for a few minutes before serving.