E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Emblematic of St. Laurence, because in his martyrdom he was broiled to death on a gridiron. In allusion thereto the church of St. Laurence Jewry, near Guildhall, has a gilt gridiron for a vane. The gridiron is also an attribute of St. Faith, who was martyred like St. Laurence; and St. Vincent, who was partially roasted on a gridiron covered with spikes, A.D. 258. (See ESCURIAL.)
It is said that St. Laurence uttered the following doggerel during his martyrdom:
This side enough is roasted, turn me, tyrant, eat,
And see if raw or roasted 1 make the better meat.