The best meal you can possibly eat while in Beijing will be served to you by a professor of applied mathematics.
His name is Li Shanlin, and his official role at Family Li's Dishes Restaurant is "adviser". Or, at least, that's what it says on the card.
The restaurant has only two tables which each seat about eight people. Book at least two weeks in advance.
As you dine on such things as squid, duck, lotus root, pork (of course), spiced bean curd, etc., Professor Li will explain, in depth, the history behind your meal. The Li Family, you see, used to guard the Imperial Chefs...and when the empire fell, the Lis "liberated" all the recipes. And you'll thank them for it.
Folks, this is the best food I've ever eaten. Plus a history lesson.
The restaurant itself is in a hutong; the rabbit-warren-like agglomeration of low houses in which the majority of Beijing-ers lived until recently. This is, if I may borrow the phrase, "old-school" Beijing here.
Your taxi driver will not be able to find this restaurant (and, if she's like mine, she'll hit several other cars on the way). Fortunately, the business card has a convenient map...or, at least, I assume it's convienent to those who are literate in Chinese. Which I am not.
Please...if you're ever in Beijing, eat at Professor Li's. Great food and fascinating surroundings (both physical and intellectual). And, if you're lucky, Professor Li will show you his scrapbook after dinner. If you're even luckier, you might be added to it.
Family Li's Dishes Restaurant
11 Yang Fang Hutong
De Nei Da Jie Xi Cheng, Beijing