To make the chicken katsu, lay the chicken on a flat surface and very carefully split the breasts in half lengthways. This will leave you with 4 very thin bits of chicken. Now cut each half into 2 widthways, so you have 8 flat pieces of chicken.
Place each chicken first into flour, then egg and finally panko breadcrumbs and set aside.
Heat some vegetable oil to 180 C and deep fry the chicken pieces until cooked and golden then set aside until you need them.
To assemble the sandwiches, lay the nori sheets on a flat surface and top with a square of cooked sushi rice. Top the rice with the spinach, carrots and some sriracha and mayo, then lay a piece of the chicken katsu on top. Sprinkle some sesame seeds on the chicken and lay the green beans on top.
Top everything with another square of rice and then flick water over the nori sheet - this will help it
Bring the edges of the nori up - as if you were wrapping a present and press the edges together so that they stick - use more water if needed. Flip the sandwich over so the seal is at the bottom and slice into two.
Serve sprinkled with some extra toasted sesame seeds.
