Reduce warmth to medium and simmer, stirring sometimes, until flavors have melded and liquid is slightly minimized, about twenty minutes; time with salt and black pepper, if wanted. rice vinegar – I am a big admirer of vinegars, and this is what provides the Beijing beef sauce its superb tang. https://paprikachilli45953.mybloglicious.com/51628451/chili-powder-sweet-paprika-powder-can-be-fun-for-anyone