I ate prahok kh'tih at a restaurant called Sugar Palm, an upmarket place that serves Khmer food to foreigners, mostly. Khmer restaurants that cater to foreigners fall into roughly three categories: places that serve food with flavors watered down for western tastes, places that serve traditional Khmer cooking as Cambodians usually eat it (which can range from uninspired to pretty good, as with any cuisine), and places that do a refined version of Khmer cuisine that is loyal to its roots. Sugar Palm falls into the last category.
Prahok kh'tih is a dip made of minced pork, coconut cream, herbs and, of course, prahok. Prahok is a very funky paste made from dried, salted, fermented river fish. It's a staple ingredient of Cambodian cooking, and subsistence diets may consist solely of prahok and rice.
In prahok kh'tih, the taste is tempered by the other elements, and the version I tried was quite delicious. It's traditionally served as a dip, warm or cold, with crudites, though I found it easier to eat it over rice.
The following day I had the opportunity to see a neighborhood full of home-brew prahok makers. Boy did that neighborhood stink!
The river fish is crushed, salted, dried, and left to ferment for months or longer. Then it's boiled in big wood-fired cauldrons with salt water to reduce the fish to a paste.
For me the chance to shoot stinking, fermenting prahok fish is much more interesting than taking photos of some old temples.