Green’s Dictionary of Slang

a cookshop under Furnival’s Inn, London, popular among legal clerks.

c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: The Dip. A Cook’s Shop, under Furnival’s Inn, where many Attornies Clerks, and Inferior Limbs of the Law, take out the Wrinkles from their Bellys.
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn) .