UPDATE: Since my last visit was on Christmas, I thought I'd come back on a less hectic day. I had a lunch special here when it was practically empty. The "empress soy protein" was decent, but a bit gooey. However the lunch special is an excellent value at only $6 and gives you a plate of food, a cup of miso soup and also an egg roll. (I also got some brown rice, which cost an extra $1.50; that's a steep price considering the whole meal was only $6.)
I'm amazed that a city as large as Chicago has no really good vegan Chinese options. Yummy Yummy is one of the only Asian places in the city that offers mockmeats, and they're not really mockmeats---just TVP or wheat gluten, which is like mockmeat from the 1980s.
I wouldn't go out of my way to try Yummy Yummy, but I'd probably stop by here if nothing else were available.
ORIGINAL REVIEW: I came here on Christmas with a vegan friend. Note to others who can't cook on Christmas: don't go to Yummy Yummy. We definitely didn't have a quaint "A Christmas Story"-esque situation with singing waiters. Other customers waited over an hour or more for their take-out orders and we waited 45 minutes for someone to take our order (given that it was Xmas, this was the only vegan-friendly restaurant open in Chicago, as we found out after calling many others). Then we waited another 40 minutes for our food to arrive. I'm not going to dock them any points for their harrowed Christmas service, as I'm sure it doesn't represent them under normal circumstances, but it does suggest they don't handle busy times well.
Yummy Yummy is tiny, with space for only 16 people. I like that they're open late (10:30 p.m.). They also have nice, simple decor. There was only one server for the whole room which can cause problems, though.
They were out of the Szechuan wontons appetizer, but we ended up with a Soy Protein in garlic sauce, and a Twice-Cooked Wheat Gluten. My friend didn't like the taste of the garlic sauce dish, nor did she like the soy protein, but I liked the dish completely. It had the perfect spice level, was full of vegetables (which she did like, too), and I thought the soy protein had a nice texture.
The twice-cooked wheat gluten fell slightly flat for me. It was passable, but nothing special. I thought the gluten was a bit too chewy and the sauce didn't have a bold flavor. Also, the only vegetables were onions and celery, neither of which I'm particularly fond of.
Yummy Yummy does have many vegan choices and I'd be curious to try some of their other dishes (they also have Thai and Korean options) and maybe one of their smoothies. The restaurant is not vegetarian, though, and the place can get packed easily, so make sure to call ahead for a table or stick to take-out. That said, this seems to be the only Chinese restaurant in Chicago that offers any type of mockmeat, so it's worth it for the novelty value alone. And, on top of it, their food is pretty good on a whole.