Pound the chicken breasts to an even thickness of about 1/2 inch and season with salt and pepper.
Set up a breading station with flour, beaten eggs, and panko breadcrumbs in three shallow dishes. Dredge the chicken in flour, dip in eggs, and coat with breadcrumbs.
Heat vegetable oil in a skillet over medium heat. Fry the breaded chicken for 4-5 minutes on each side until golden brown.
Assemble the bowls by dividing cooked rice, topping with shredded cabbage, carrots, green onions, and sliced chicken. Drizzle with tonkatsu sauce and garnish with sesame seeds.