Like the Xmas dinner, the leftovers reheated can be a nice meal, for a single person who maybe doesn’t cook… it’s possible she sent a click clack (Tupperware) home with the 4, to give to SP. but since he wasn’t home, they decided to incorporate that meal into their own meal rather than it go to waste. It might have been prepared separately and boxed up ready to go before the 4 arrived at EP for lunch. EP saying I made this for SP since he couldn’t be here- saying its special meal. EP wouldn’t have expected the 4 to eat it, rather expecting it goes to SP who has a relapse of stomach prob & dies, not suspicious as he’s been very ill before.
Imagine her surprise seeing SP alive and well at hospital and the others sick and dying ….