This sweet, salty, cooked Japanese paste was made famous by Nobu Matsuhisa who used it in his legendary grilled black cod. Peter Gordon explains more about den miso and uses his version in this recipe for miso beef ribs on the bone.
Whisk together all ingredients, then over a low heat slowly bring to the boil, whisking gently as it heats up — it can easily catch on the bottom. Once bubbling, lower to a simmer and cook 5 minutes, stirring often. Cool before using. It keeps covered in the fridge for 4 weeks.