sandwich-splaining

When someone tells you how to craft your sandwich, as if they have a superior knowledge of the sandwich arts.

1: You know, the pickles should be sliced vertically on top of the mustard, and you really should use shredded iceberg lettuce---

2: Stop sandwich-splaining! Next are you going to tell me I have to cut it in half diagonally?!?

1: Yes, yes I am.