How to Make It
Combine water, rice, vinegar, salt, and sugar in a medium saucepan, and let stand 10 minutes. Turn heat on medium-high, and bring to a boil. Reduce heat to medium; cover and cook until rice is tender, 18 to 20 minutes. Transfer rice to a baking sheet, and allow to cool, about 10 minutes.
Combine mayonnaise and wasabi in a small bowl, set aside.
Heat 2 tablespoons of the oil in a large nonstick skillet over medium-high. Add rice to skillet; using wet hands, press rice, forming a large rice patty. Let rice cook, undisturbed, until lightly golden on bottom, about 5 minutes. Brush top of rice cake with remaining 1 tablespoon oil. Carefully place the back of a small pizza pan over skillet, and flip skillet to invert the rice cake. Slide rice cake back into hot skillet over medium-high, and cook other side until lightly golden and crisp, about 5 minutes. Remove from skillet, and let cool, about 10 minutes. (Rice patty can be chilled in freezer 5 minutes to speed up the process.)
Spread wasabi mayonnaise in a thin layer over rice patty leaving a 1-inch border. Arrange smoked salmon in a ring around outer edge of mayonnaise layer. Arrange cucumber slices in a ring overlapping salmon. Arrange tuna slices overlapping cucumber. Arrange avocado slices in center of pizza. Sprinkle jalapeño slices evenly over pizza, and spoon ginger slices in center of avocado slices.
Combine soy glaze and ponzu sauce in a small bowl. Drizzle soy mixture over pizza. Sprinkle with sesame seeds.