Place all your ingredients into the blender, in order of hardest to softest (mainly to avoid splashing!). This would be apple, onion, garlic, ginger, red miso paste, optional gochujang, brown sugar, honey, mirin, sesame oil, lemon juice and finally, soy sauce.
½ cup soy sauce, 3 tbsp brown sugar, 1 tbsp mirin, 1 tbsp honey, 1 tbsp red miso paste, ¼ apple, ¼ onion, 1 garlic, ½ tbsp ginger, 1 tsp sesame oil, 1 tsp lemon juice, 1 tbsp gochujang