Sweat down onion and scallion over medium heat until melted.
Deglaze with soy.
Add ketchup, Worcestershire sauce, and vinegar to the mixture.
Simmer the sauce for an hour, stirring often.
Puree in a blender, working in batches.
Serve with fried chicken, pork, or as an alternative to traditional barbecue sauce.
Recipe and image used with permission and courtesy of Wusthof. All rights reserved. Recipe by Chef Richie Nakano, chef and owner of Hapa Ramen, San Francisco, CA.