Heat oil in a deep fryer or large pot to 350°F (175°C).
In a bowl, mix cornstarch and all-purpose flour.
Beat the egg in a separate bowl.
Place panko breadcrumbs in a third bowl.
Coat each salmon cube first in the flour mixture, then dip in egg, and finally coat with panko breadcrumbs.
Carefully deep fry salmon bites in batches until golden brown and crispy, about 3-4 minutes per batch.
Remove bites with a slotted spoon and drain on paper towels.
In a small bowl, whisk together mayonnaise, sweet chili sauce, sriracha, and lime juice to make the bang bang sauce.
Arrange salmon bites in a neat pile on a white rectangular plate.
Drizzle bang bang sauce over the bites.
Garnish with chopped green onions and sesame seeds before serving.