Le Commensal is a great option for a quick vegan meal, as long as you don't mind paying extra. I was attending a conference at 89 Chestnut, and this place was extremely close by, and made for a nice quick lunch option.
I tried quite a number of dishes, and everything ranged from good to excellent. I particularly liked the vegan leek quiche and the seitan bourguignon. I wish they had more vegan desserts, though the "soya cake" (tofu cheesecake) and carrot cake were both good.