Green’s Dictionary of Slang

(US prison) Salisbury steak; hamburger.

1975		J. Wambaugh Choirboys (1976) 142: We wake our prisoners at five A.M. and serve them meals of red death, Gainesburgers and donkey dicks.
1986		J. Ellroy Silent Terror 67: The mess-hall slang for Salisbury steak, hot dogs and breakfast jelly was respectively, ‘Gainesburgers,’ ‘donkey dicks’ and ‘red death’.