The finished recipe. Chicken Katsu SandwichIngredients 1 to 6. 150 g Chicken breast (One breast, butterflied and flattened to about 1 cm so it cooks through before the crumb burns. Weighed raw. The same piece weighed after cooking has lost water, so the protein per gram is higher and the total would come out about a quarter over.). 1 tbsp (10 g) Plain flour. 1 large, about 55 g Egg (For the coating. Not all of it sticks, but all of it is counted, which is the honest way round.). 25 g Panko breadcrumbs (Panko. Most of what is on the plate after coating ends up on the chicken.). 2 tsp (10 g) Rapeseed oil (Shallow-fried in a thin film, not deep-fried. Deep-frying would put an unknown amount into the crumb.). 2 slices, about 72 g White breadIngredients 7 to 11. 60 g White cabbage. 1 tbsp (15 g) Tomato ketchup. 1 tsp (5 g) Worcestershire sauce. 1 tbsp (15 g) Light mayonnaise. To taste SaltStep 1. Season the flattened chicken. Dip it in the flour, then the beaten egg, then press it firmly into the breadcrumbs on both sides.Step 2. Heat the oil in a non-stick pan over a medium-high heat. Fry the chicken for four minutes a side, until the crumb is deep golden and the thickest part is no longer pink. Rest it on kitchen paper.Step 3. Stir the ketchup and worcestershire sauce together. Shred the cabbage as finely as you can.Step 4. Spread the mayonnaise over one slice of bread and the sauce over the other. Lay the cabbage on, the chicken on top, close, trim the crusts if you like, and cut into two.