The Field's Institute is at the corner of College and Spadina. If you're there for a week or two of workshops, that means you're going to be looking for lunch and dinner places that are: close; reasonably priced; and good for groups.
New Sky fits the bill, so I've been there several times. The food is pretty good, though there are other places in Toronto's Chinatown that are better, but less conveniently located. Three stars seems about right, but I somehow suspect I'll wander in again the next time I find myself at UT for some reason or other.