Chicken Katsu Sandwich Sushi (Onigirazu)

Sushi Rice

• 400 g sushi rice
• water, to soak

Katsu chicken and assembly

• 100 g panko breadcrumbs, toasted
• 40 g extra virgin olive oil
• 500 g water
• 80 g rice wine vinegar
• 60 g caster sugar
• 10 g sea salt
• 40 g plain flour
• 2 pinches sea salt
• 2 pinches ground black pepper
• 500 g chicken breast butterflied, cut into squares (approx. 7 x 7 cm).
• 2 eggs, beaten
• 8 nori sheets
• 100 g cabbage (approx. ⅛), shredded
• 4 tbsp tonkatsu sauce
• 2 tbsp Dijon mustard
• 2 tbsp Kewpie mayonnaise