This is still one of my absolute favorite Pittsburgh restaurants, even after my going fully vegetarian a few years back. Given that 80% of the menu is steak-related, I think that's a testament to the quality of all the food. They have a wood-fired veggie sandwich that still makes me weep happy tears, and they have an always tasty veggie empanada-of-the-day (as well as a daily meat-focused one). In addition, there are several side dishes that are vegetarian and excellent, including scrumptious salads, potatoes, and veggies.
I'm sure other reviews have mentioned how crowded it is, because the word is out about the ridiculous deliciousness of Gaucho. Most of the time you will be waiting in a long line spiraling outside the door. I'ts still worth it. They seem to move people inside and seat people at a good pace. I tend to go right when they open for lunch when the line isn't too bad, and plan to heed the advice of others and call in a take-out order to avoid the wait. Heavenly food.