Add 4 tbsp Worcestershire sauce, 2 tbsp tomato ketchup, 2 tbsp Japanese soy sauce (koikuchi shoyu), 2 pinches light brown sugar and 2 tbsp toasted white sesame seeds to a bowl and mix thoroughly until well incorporated.
Nagoya Style Red Miso Tonkatsu Sauce (10 mins)
Add 100 ml dashi stock (or water), 2 tbsp red miso paste, 1 tbsp sake, 1 ½ tbsp mirin, 1 tsp Japanese soy sauce (koikuchi shoyu), 2 tbsp light brown sugar and ½ tbsp toasted white sesame seeds to a small saucepan and bring to a boil over a medium heat. Then, lower the heat and summer for 5-10 minutes or until thickened.
Remove from the heat and stir in the sesame seeds.
Transfer to a bowl for dipping or simply pour it directly onto the katsu.
Toasted Sesame Tonkatsu Sauce (10 mins)
Add 4 tbsp toasted white sesame seeds to a dry pan and heat on medium/medium-high. Stir continuously and toast the sesame seeds until slightly golden and you can smell the aroma.
Grind the seeds down to a powder using a mortar and pestle (or spice blender).
Mix the ground sesame seeds with 4 tsp Japanese soy sauce (koikuchi shoyu), 4 tsp Worcestershire sauce, 2 tbsp tomato ketchup, 2 tsp sugar and 2 ½ tbsp water.