Add 2 tsp sugar and a splash of water to a small saucepan. Heat over medium, stirring until the sugar has dissolved. Stop stirring, and continue to heat the sugar until it turns amber. Avoid mixing, and swirl the pan occasionally for even coloring.
Once the sugar has transformed into a deep amber syrup, pour in 3 tbsp mirin a little at a time and swirl the pan to distribute. The mixture will sputter aggressively as you add the mirin, so keep back and wear protective clothing when you do this.
Reduce the heat to medium-low and add 2 tbsp apple juice, 1 tsp ketchup, ½ tsp yellow miso paste (awase), ½ tsp Worcestershire sauce, and 1 pinch dashi granules to the pan. Stir continuously for 2-3 minutes, or until the miso is completely dissolved. Let it bubble gently for 3 minutes while stirring, then take the pan off the heat.
Add ½ tsp cayenne pepper powder, ½ tsp garlic powder, ⅛ tsp ground white pepper, ½ tsp ginger powder, ½ tsp onion powder, and mix.
Add 3 tbsp Japanese soy sauce (koikuchi shoyu), and ½ tbsp toasted sesame oil. Pinch ½ tbsp toasted white sesame seeds between your fingers, then sprinkle them into the sauce and mix well. Finally, stir in 1 tsp grated apple and then transfer to a serving bowl or clean airtight container for storage.
Serve with your favorite grilled meats and vegetables. Enjoy!
Notes
Stop the caramel at deep amber. Look for strong toffee smell and the first faint wisps of smoke rising from the surface.Add soy sauce off heat. Soy sauce contains over 300 volatile aroma compounds that heat can destroy within seconds. Stir it into the sauce after removing the pan from the stove.Rest overnight before judging flavor. A freshly made batch tastes sharp and disjointed. After 8 to 12 hours in the refrigerator, the components diffuse and merge into a cohesive profile.Refrigerate in an airtight container for up to 1 week.