Khao piak sen
Khao pun nam phik
UPDATE I: Pok Pok owner and Thai food evangelist Andy Ricker helped me better understand the confusing nomenclature of khao soi vs. khao soi: "Khao soi means 'cut rice' and refers to the noodles used, so although it is the name of a dish, different dishes can have the same name. Long ago, Northern Thai khao soi probably was made from cut rice noodles too, even though now it is made with wheat noodles. To confuse matters, and you'd need to speak to a linguist and a food historian about this, a long time ago when wheat was introduced, they had no reference for it except rice. So wheat is called Khao Salee (Khao means rice), or a different form of rice so perhaps they were referring to wheat noodles."
UPDATE II: Andy then referred me to Thailand-based author/photographer Austin Bush who has written guidebooks all over Southeast Asia. Austin says: "With all respect to my buddy Andy—I think he's incorrect about the "cut rice" theory. Yes, translated directly, the Thai words "khao soi" do literally translate as "cut rice", but I suspect that this is simply a coincidence. More likely, the word is the Thai pronunciation of the Burmese hkauk hswe (or khauk hswe or kauk swe) which is their general term for noodles...my guess is that, again, since khao soi probably comes from a word that means simply noodles in Burmese, it has come to be attached to a few different noodle dishes. Incidentally, it's not only available in Laos, and I've encountered it in Myanmar and northern Thailand." So the mystery remains!