This is an excerpt from Een notabel boecxken van cokeryen
(Netherlands, ca. 1510 - C. van Tets, trans.)
The original source can be found at
Willy Van Cammeren's website
To make another ieleye. Take fish and cut them in pieces according to whether you want them small or large, but it must be washed very clean, then it must be dried very well from the water. Then take the half [i.e. half that quantity in] wine and the third [i.e. a third of that quantity in] vinegar. You will boil the aforesaid fish well in this, and see that you skim it clean, and remove all the scum so that you take off all the white and there is none left, and let it boil until it is enough. So take it out of the water and let it drain well in a colander or on a wooden mat where it may drain well. Then take spices that are strong. That is, lots of galingale - some do not put galingale in, but other spices - much saffron, nutmegs, ginger, grains of paradise, mace and grind it up small in a mortar, each by itself or all together, to a powder, and put it through a strainer with the broth in which the fish was boiled. Whoever also wants to, takes the scales or a piece of the skin of the fish and cuts it up and puts it into he broth and one shall let that simmer until it is reduced almost to a third or a little less. And when it is boiled lay the fish in dishes as they ought to lie. That is, with their scales on the bottom and with the insides outwards. Then take as many dishes as you want to make and fill them with fish. Then you shall pour the sauce over them and let them cool and so you will set them where they may keep cool.