How can it be possible to leave a restaurant with a nasty taste in your mouth - despite the fact the food has been delicious?
It happens when top-level staff forget an age-old maxim of the service industry: the customer is always right.
The restaurant in question is the otherwise excellent Tian He Sheng near the University of International Business and Economics (UIBE) and the controversial dish of the day in our case was the san wen yu ci shen salmon.
The sashimi-style dish is essentially comprised of bite-sized chunks of raw fish which can be dipped in soy sauce. Raw - not frozen, as our's patently was.
As the voices of 12 diners rose in protest, the duty manager reluctantly, and somewhat petulantly, conceded defeat, despite a continued insistence that the dish is always served like this. (It isn't: I had precisely the same thing served to perfection a week before).
If the point seems laboured it's because I believe it's a supremely important one in a culinary market as competitive as Beijing's.
Would I go back?
The surprising answer is yes, and here's why. The food is good and reasonably priced, the service typically excellent and the atmosphere lively.
Picture menus help the average laowai make an informed guess, if their Chinese isn't up to scratch.
The si xi wanzi (also known as meatballs) are a juicy, chunky proposition at 3 yuan (36 cents) apiece. The gravy makes a great dipper for anything else on the table.
Another star dish is the garlic beef wrapped in a lotus leaf he ye suan xiang niu liu which comes in at a reasonable 18 yuan (US$2.20). If chicken drumsticks make your mouth water, check out the zhu xiangji at 26 yuan (US$3.10).
The fish dish, song shu gui yu, is pricier at 58 yuan (US$7) but offers plenty of interest for the taste buds.
King of the vegetable patch here must be the mushroom-based you cai xiang gu, a snip at 8 yuan (96 US cents). A friend who is something of a mushroom connoisseur declared them "amongst the best I've ever had in Beijing."
The banter amongst the polite waiting staff, who yell out arriving dishes, keeps the atmosphere lively and the portions are fair for the price paid.
Location: 38 Huixinli, Chaoyang District.
Tel: 6495-1583
(Beijing Weekend December 5, 2002)