There was certainly a meal, and Aunt Jessie's sandwiches would assuredly be thick and probably no mustard!
"Fortitude"
Hugh Walpole
In old Christmas carols there are frequent allusions to mustard.
"England in the Days of Old"
William Andrews
In the familiar old carol, sung annually at Queen's College, Oxford, is a line:- "The boar's head with mustard."
"England in the Days of Old"
William Andrews