Seriously you just have got to get there early on Saturday morning and check out the Pittsburgh Strip District.......well worth your time. Lots of street food, freshly baked breads, imported cheeses and specialty shops, and it's right across the river from Heinz Field, plenty of parking in the area to boot. The link below tells you more -
http://www.discovertheburgh.com/strip-district-guide/
http://www.discovertheburgh.com/strip-district-guide/