This is an excerpt from Forme of Cury
The original source can be found at the Project Gutenberg website
CRUSTARDES OF FLESSH. XX.VII. XIIII. Take peiouns, chykens, and smale briddes smyte hem in gobettes. & seeþ hem alle ifere in god broþ wiþ veriaws do þerto safroun, make a crust in a trape. and pynche it. & cowche þe flessh þerinne. & cast þerinne Raisouns coraunce. powdour douce and salt. breke ayrenn and wryng hem thurgh a cloth & swyng þe sewe of þe stewe þerwith and helde it uppon the flessh. couere it & bake it wel. and serue it forth.
Other versions of this recipe:
Crustate of flesshe (Liber cure cocorum [Sloane MS 1986])
Crustardes of flesch (Fourme of Curye [Rylands MS 7])