Prepare the ingredients
Wash and dry the fresh produce. Cut out and discard the core of the cabbage; thinly slice the leaves. Cut off and discard the root ends of the scallions; thinly slice on an angle, separating the white bottoms and green tops.
Cook the rice
In a small pot, combine the rice, a big pinch of salt, and 1 cup of water. Heat to boiling on high. Once boiling, reduce the heat to low. Cover and cook, without stirring, 12 to 14 minutes, or until the water has been absorbed and the rice is tender. Turn off the heat. Fluff the cooked rice with a fork. Cover to keep warm.
Make the slaw
While the rice cooks, in a large bowl, combine the sliced cabbage and white bottoms of the scallions, sweet chili sauce, and vinegar; season with salt and pepper. Set aside to marinate, stirring occasionally, at least 10 minutes. Season with salt and pepper to taste.
Coat & cook the chicken
While the slaw marinates, in a medium bowl (or large resealable bag), combine the flour, cornstarch, and half the togarashi seasoning. Stir (or shake) to combine. Pat the chicken dry with paper towels; season with salt and pepper. Add to the flour mixture and toss (or shake) to coat. In a medium pan (nonstick, if you have one), heat a thin layer of oil on medium-high. Once the oil is hot enough that a pinch of the flour mixture sizzles immediately when added, add the coated chicken in an even layer (shaking off any excess coating before adding). Cook, without stirring, 3 to 4 minutes, or until lightly browned. Continue to cook, stirring occasionally, 3 to 4 minutes, or until cooked through. Transfer to a paper towel-lined plate; immediately season with salt and the remaining togarashi seasoning.
Make the tonkatsu mayonnaise
While the chicken cooks, in a bowl, combine the tonkatsu sauce and mayonnaise. Season with salt and pepper to taste.
Serve your dish
Serve the cooked chicken, cooked rice, and slaw with the tonkatsu mayonnaiseon the side. Garnish with the sliced green tops of the scallions. Enjoy!