Salmon Sushi Bake

Place the rice into a large mixing bowl and cover with cool water. Swirl the rice in the water, quickly drain the rice and repeat until the water is clear. This will take 3 to 6 rinses. Drain the rice in a colander.
Combine the rice, kombu, and 2 cups of water into a medium saucepan* and place over high heat. Bring to a boil, uncovered. Reduce the heat to low and cover. Cook for 15 minutes. Remove from the heat and let stand, covered, for 10 minutes. Discard the kombu.
To make the sushi vinegar mixture combine the rice vinegar, sugar, and salt in a small bowl and heat in the microwave on high for 30 seconds.
Transfer the rice into a large mixing bowl, Use a nonmetallic bowl to prevent any interaction with the rice vinegar. Add the vinegar mixture. Fold the mixture through the rice using a slicing motion, being careful not to crush the rice.

Preheat the oven to 425 F degrees. Spray the bottom of your baking dish with a non stick spray and set aside.
While the rice is cooking marinate the chopped salmon. Add half the sliced onions, Kewpie, soy sauce, sriracha, and rice vinegar. Stir to coat the salmon.
Press the rice into the bottom of the baking dish. Sprinkle on the furikake. Top with the salmon mixture. Bake uncovered for 15 to 20 minutes or until the salmon is cooked through and the mixture is bubbling.
Remove from the oven and top with sesame seeds, the other half the green onions, cucumber, and avocado. Serve with additional toppings as desired and nori for making bite-size pieces.