Green’s Dictionary of Slang

(US) a boiled or roasted hog’s (or bullock’s) head with the eyes and jowls removed.

1834		Morn. Advertiser (London) 5 Dec. 1/3: In the forecastle they had bum-sturgeon, which is minister’s muns (bullock’s head) made into soup.
1855		C.G. Parsons Inside View of Slavery 115: The upper part of a pig’s head – ‘the minister’s face’ – was on the table.
1873		W.H. Thomes Slaver’s Adventures 155: I’ll give up eating old hoss and ministers’ faces, and have a farm and lots of pigs.
1913		Day Book (Chicago) 28 Aug. 15/1: I [...] saws her take a pail and go a quarter of a mile for water, fry the ‘minister face and crush’ [...] and make coffee.
1926		N. Klein ‘Hobo Lingo’ in AS I:12 652: Minister’s face — pigs head served in cheap restaurant.
1931		Irwin Amer. Tramp and Und. Sl. 129: Minister’s Head. – Boiled pig’s head.
1949		Monteleone Criminal Sl. (rev. edn).