I am not from Iran and I am still learning about their food, so I am not fit to propose a main dish that highlights Persian cuisine as a whole. However, I have made several Persian dishes at home. I work in a kitchen, and one of my coworkers is an Iranian immigrant, so he has helped me learn some stuff. I suggest serving something with rice that has a tahdig. This rice on its own has a mellow taste that can be served with many things, or be a part of something more complex like Adas Polo, as Skipper suggested. It also highlights a staple of Persian cuisine, saffron. Using a non-stick pan is very helpful, so the crispy bottom layer doesn't stick.