Gruyau France, 14th century. A gruel of barley and Almond Milk. Original recipe from Le Viandier de Taillevent 93. A Gruel of Husked Barley.
Some people grind it and strain it.
It should not be at all too thick. Scully, Terence, ed. Le Viandier de Taillevent. An Edition of all Extant Manuscripts. Immediately reduce heat to a simmer, and stir in the sugar and salt.