I love Zenith! I haven't been down in an age, but when I think of my favorite spots in the city, this is definitely one of them. I took my parents here for their buffet brunch when I'd had it with the shortlist of available options in Pittsburgh (either a chain or WAY expensive) and even they enjoyed it.
There is never a long list of options for hot entree but guaranteed you'll still have a tough time deciding. The decor is unlike anything else in PGH - fronted by a rummage friendly antique store. You almost feel like you're walking into a surprisingly cozy back stockroom to eat with the owners.
I'm not a vegan or a vegetarian, but Zenith usually makes me feel like I easily could become one and not miss too much!