Sushi rice is a short grained starchy rice that becomes sticky as it cooks and hold together well making it the ideal rice for a pizza base. The sushi crust is slightly crispy yet chewing in texture.
In fine sieve, rinse rice in 3 changes of cold water, stirring vigorously until water runs clear. Drain well.
In a medium saucepan, bring rice and water to a boil over high heat. Reduce heat to low, cover and simmer for 15 minutes. Remove from heat and let stand covered for 10 minutes.
In a large bowl, combine rice vinegar, salt and sugar. Stir until sugar and salt have dissolved. Add to warm rice and mix gently to coat. Let stand for 10 minutes.
Divide rice mixture into 4 balls. On a piece of parchment paper, flatten each ball into a 5-inch round.
Heat 4 tsp of oil in a large non-stick skillet over medium-high heat. Cook one sushi crust, turning once, until crisp and lightly golden, about 2 minutes per side. Repeat with remaining sushi crusts.
Transfer to cutting board and cut each crust into quarters. Top with avocado, cucumber, salmon and green onions. Top with kelp caviar, sprinkle with sesame seeds, and drizzle with wasabi aioli. Serve.
In a medium bowl, whisk egg yolk with mustard. Whisking constantly, slowly drizzle in oil until mixture is emulsified. Whisk in wasabi powder and rice vinegar.