The sauce for serving oyster omelette is different from may many region, but mostly ketchup or chili sauce based. The sauce consistency is thick and gooey with a balance of citrusy, spicy, nutty, tangy, sweet and savoury. The oyster omelette sauce sometimes contain some peanut butter to give it a litte nutty aftertaste without overpowering the sauce. The Japanese version of oyster omelette or kaki tamago sauce also comtain some red miso paste, while the Korean give their signature gochujang on the sauce, so pretty much the sauce is adjustable as long as it comforts your licking preference.