Step 1

Whisk mayonnaise, Sriracha and sesame oil in a small bowl. Set aside.

Step 2

Combine cabbage, zucchini, carrot and scallion whites in a large bowl. Sprinkle with rice flour and salt and toss to coat. Beat eggs in a small bowl, then pour over the vegetables and stir until evenly combined.

Step 3

Heat canola oil in a large nonstick skillet over medium-high heat until shimmering. Add the vegetable mixture, pressing gently on the top and sides with a spatula to shape it into a large pancake. Cook until a golden crust forms on the bottom and edges, 6 to 9 minutes. (Reduce heat, if necessary, to prevent burning.) To flip, carefully place a large plate or inverted rimless baking sheet over the pan and quickly invert. Slide the pancake back into the pan, browned-side now facing up. Continue to cook until the vegetables are tender and the bottom is golden, 3 to 4 minutes more.

Step 4

Slide the okonomiyaki onto a serving plate. Drizzle with the reserved mayonnaise mixture and sprinkle with sesame seeds and scallion greens.