The grilled cheese aspiration was introduced with Nightlife, as the result of a failed (or not-failed, depending on your goal
) experience with the ReNuSenso Orb. All the Sim wants to do after being changed to this aspiration is grilled-cheese related, and the LTW for it is to eat 200 grilled cheese sandwiches.
I think in another thread you mentioned only having Uni, so you wouldn't have this in your game.