Khai katha, literally 'pan eggs', is a dish I came across in virtually every Thai town that bordered the Mekong River. It's apparently a Vietnamese take on fried eggs for breakfast, although I don't recall having seen it there. The eggs, fried up in a tiny aluminum pan (the katha), are supplemented with thin slices of kun chiang (Chinese sausage), muu yor (Vietnamese sausage), sliced green onions, and unusually for Thailand, ground black pepper. The dish is also accompanied by bread, which at the better places, takes the form of a freshly-toasted French-style baguette (although it must be said that the Thai ones are nowhere near as good as their Vietnamese and Cambodian counterparts).
The khai katha above is from Nong Khai, where after meeting it for the first time by the city's morning market, noticed the dish just about everywhere on the drive back to my hotel. Khai katha is big in Nong Khai. The bread shown in the background is a half-arsed Thai attempt at bánh mì, a Vietnamese-style sandwich, but included a few thin slices of the previously-mentioned sausages and little more.
Another version in the town of That Phnom, in Nakhorn Phnom province, was more like an omelet:
Rather than the muu yor they used cheap hotdogs and ground pork, and in place of the French-style bread, toasted white bread. It was a low point in my khai katha experience.
Undeterred, I bought two katha in Mukdahan, and since returning home have been making the dish for breakfast nearly every day, using tasty free-range eggs, muu yor from Ubon Ratchathani and decent French bread from La Boulange, and have refrained from cooking the hell out of the eggs.