This is an excerpt from Liber cure cocorum [Sloane MS 1986]
(England, 1430)
The original source can be found at
Thomas Gloning's website
Lamprayes in browet. Take lamprayes and scalde hom by kynde, Sythyn, rost hom on gredyl, and grynde Peper and safrone. welle hit with alle, Do þo lampreyes and serve hit in sale.
Other versions of this recipe:
Lamprays in brewte (Gentyll manly Cokere (MS Pepys 1047))
Lamprey in Bruet (A Noble Boke off Cookry)
FOR TO MAKE LAMPREYS IN BRUET (Forme of Cury)