Yuen's Restaurant is a Vietnamese/Chinese restaurant in the Columbus Square plaza. The menu seems to offer a couple of vegetarian options, but upon further examination, Yuen's is actually a vegetarian wasteland.
Certain cuisines are famous for being less than vegetarian-friendly. Some of the most notable nations for ignoring veggies are Brazil, Argentina and Vietnam. Yuen's being a Vietnamese restaurant, keeps the tradition going (as a side note, Lac Viet in the North Market has a vegetarian banh mi sandwich; they are at least extending an olive branch to meatless eaters).
The menu is split into Chinese and Vegetarian choices. There are a number of tofu dishes. Since one is ma po tofu, a dish noted for combining tofu and pork, I asked what a vegetarian could order from the menu. I was given one option: vegetable tofu, an item that isn't listed on the menu.
While the vegetable tofu was competently prepared, it was hardly spectacular. Overall, it didn't make me long to return.
Luckily for diners, there are plenty of vegetarian options in the Columbus Square plaza as well as along 161 and Cleveland. While Yuen's is not recommended for vegetarians, there are plenty of vegan and vegetarian options in the area (Solay Bistro, Nazareth Deli, et al.) that can serve as a suitable replacement.