Combine all the ingredients in a bowl and mix together with a whisk. That's it!
Give it a taste. If you'd like it sweeter, add some brown sugar. If you'd like a more vinegary taste, add a bit more apple cider vinegar.
Story Behind this Recipe
I was making hamburgers and wanted to use brown sugar BBQ sauce. I looked up a recipe online and started making it, but I was missing about half of the ingredients. After all the substitutions, it was a different recipe altogether. It was quite tasty, so I wanted to share it ^_^
The sauce is a little watery, so depending on how you use it, you may want to reduce it or add about a tablespoon of katakuriko (or corn starch) to thicken. In that case, simmer in a pot until reduced.
I was making hamburgers in a frying pan, so I added the sauce to the frying pan after the burgers cooked and simmered until they were well-coated.