Browned Fish with Tahini/Sesame Paste Sauce

I found this delicious recipe in al-Baghdadi’s thirteenth-century cookbook, where it is called Samak Maqlu bi-Khal wa-Rahshi (fish fried with vinegar and tahini/sesame paste). We still use the same medieval indigenous name rahshi (tahini), except that we pronounce it rashi. The quantities suggested below are my improvisation.