SPOILER:
The easiest way to make the cheese sandwich is to tell the girls you need to pick up some more cheese, run to the grocery store, but a cheese sandwich (AND CHEESE), run home, climb in through the window, and put the cheese sandwich down in the refrigerator. Now go back outside, (With the cheese), and walk back in. She sees you have cheese, so she's not suspicious. now go back, pretend to make something (Throw out all the ingredients needed), and give here to premade sandwich.
Telling her to make one results in one of the three (Depending on Karma):Takes a knife and kills you, makes a perfectly good sandwich, burns herself. What she does when she burns herself is up to persuasion: Nothing, put it under ice cold water, and (only if your persuasion is under 23) go on a murderous rampage.
