I think it's going to remain a secret. Every Shaolin monk I approach online says the same thing, essentially: "yes they are vegetarian, but I have been given permission to eat meat as the fighter class (or whatever)." And then, the vegetarian information just says they are "vegetarian".
"The monks of Shaolin Temple strictly observe Buddhist commandments and monastic rules such as keeping single, taking vegetarian diet, dressing Buddhist clothes and living in the temple which formed the characteristic Shaolin tradition. Shaolin monks adopt the method which is the unity of Chan meditation practicing, Kungfu practicing and abstinence practicing as well as praying to Buddha to do self-cultivation.” Ven. Abbot Yongxin said.
— http://www.shaolin.org.cn/templates/EN_ ... ntid=10225
"Dejian and his disciples tend small groves of bamboo and terraced plots of vegetables and herbs. They adhere to a vegetarian diet and harvest wildflowers, mosses, and roots to make medicines for everything from insect bites to liver problems. People come from all over China seeking advice for various ailments. Usually they want treatment only for symptoms, says Dejian, but "Chan Wu Yi treats the whole person. When the person is healthy, the symptoms disappear."
His habit is to rise at 3 a.m., first meditating, then practicing breathing techniques designed to strengthen the chi. There was a time when he would spend six hours or more practicing traditional kung fu forms every day, but now he is pulled by some of the same modern forces that are reshaping the Shaolin Temple. Responding to requests to lecture, raising money to finish the construction, training his disciples, and of course attending to the stream of visitors—all compete for his attention and energy."
— http://ngm.nationalgeographic.com/2011/ ... win-text/2
^^^ Okay, that's a little more informative in that it lists some specifically unusual items like wildflowers and mosses, but not really anything terribly useful. The next paragraph or so explains that he is constantly working with his body and energy all day long, so I think the secret is in the practices and not the food.
So,there are the Shaolin Temple disciple monks who are vegetarian, celibate and the warrior monks who eat meat and drink alcohol. And that's about all I'm going to learn about that!