Yes, Spring World has a Yunnan menu (with plenty of mushrooms), along with a Sichuan menu. I was surprised at the amount of seafood on the Yunnan menu, since Yunnan is landlocked (we did have a lot of good carp and other lake fish, but very little shrimp or crab), but of course we shouldn't assume that a cuisine depends on local products. When I return to Chicago perhaps I will schedule a Yunnan-focused dinner at SW.
Spring World serves "Across the Bridge" Noodle Soup which is a Yunnan classic. (It is ultimately a noodle soup - just fine - but not as amazing in comparison to other dishes, but it is a very traditional Yunnan dish).
Here is the story from www.chinaculture.org
Having originated in Mengzi County of Southwest China's Yunnan Province, the Rice Noodles Crossing the Bridge dish boasts a history of more than 100 years. With continuous renovation by chefs specializing in Yunnan Cuisine , the dish has enjoyed growing fame both at home and abroad, and every visitor to Yunnan should definitely try the famous snack besides taking in the breathtaking natural scenery.
There is a beautiful legend concerning the birth of the rice noodles. Legend has it that South Lake in Mengzi County once boasted extremely beautiful scenery, where a great many literary scholars would work hard to become an official. One of them was a Xiucai (person who passed the imperial examination at the county level in the Ming (1368-1644) and Qing (1644-1911) dynasties) surnamed Yang.
Yang often went to read books at the pavilion located in the middle of the lake. Although his wife would always take him something to eat, Yang was always so deep into his studies that he often forgot to eat. By the time he would remember, the food had already become cold, and thus his health deteriorated.
One day, much concerned about her husband, the wife killed a hen, and cooked it in a pottery pot. Then, she took the chicken and soup to her husband. After a while, she came back to clean up. However, what she saw was the food left untouched by her husband who was intently concentrating on his book.
With a sigh, she decided to heat it for her husband to eat later, but to her surprise, the pot was still warm when she touched it. Uncovering the pot, she found a layer of chicken oil floating atop the soup, which, together with the pottery container, helped preserve the heat. From then on, she cooked in this way to keep the food warm, and her husband was always able to eat warm food.
Later, many people cooked rice noodles in the wife's innovative way, and found it really delicious and fresh. Since Yang had to cross a bridge to reach the pavilion in the middle of the lake, the rice noodles cooked in this way was named "Guoqiao Mixian " (literally "Rice Noodles Crossing the Bridge").
The rice noodle dish contains three parts: the soup, any kind of sliced meat, and rice noodles and fresh vegetables.