This is an excerpt from Libre del Coch
(Spain, 1520 - Robin Carroll-Mann, trans.)
The original source can be found at
Mark S. Harris' Florilegium
183. Trout in crust or roasted or boiled. The trout must be scaled, and if you wish to make it in crust, cast in pepper and a little ginger. And if you wish to cook it in some other manner, such as roasted or boiled, cause water to boil in a casserole, and cast in the trout. And when it is almost half cooked, cast in a little salt so that it should have good flavor. And then cast a half glass of vinegar into the casserole, because the vinegar will make it firm, so that it shouldn't break; and eat it with pepper, and with a little broth of the pot or of the casserole itself.
And if they want to eat it roasted, it must be eaten with orange juice and water and salt and a little oil, and all the good herbs; and prepare the plate of the roast trout. And cast this juice on top of everything. And know that the best morsel of it is the snout.
Other versions of this recipe:
To make a fish pastry from trout (Das Kuchbuch der Sabina Welserin)