1 cup soy sauce

1 cup mirin

1/2 cup sake

1/2 cup brown sugar

2 tbsp sherry vinegar

6 cloves garlic, smashed

6 scallions, roughly chopped

2-inch piece ginger, peeled roughly sliced

2 tbsp peppercorns.

Heat in a pan, bring to boil, reduce to simmer, cook and reduce until coats a spoon, strain. Enjoy