Ge-hyrstan

According to the Old English Dictionary:

-hierstan;

ge-hyrstan

p. -hyrste; pp. -hyrsted, -hyrst To fry, roast; frīgĕre :-- Hí cócas gehyrstan cooks roasted them, Ps. Th. 101, 3. Gehyrsted síe frīgētur, Cot. 87. Gehyrst hláf frixius pānis, Ælfc. Gl. 66; Som. 69, 69; Wrt.Voc.41, 23. Et ðas sídan ðe gehirsted is eat this side that is roasted, Shrn. 116, 6. [O. H. Ger. giharstit frixus.] ge-hyrstan