Clearly this was meant to be pizza: Note the familiar wedge shape, the doughy base, the midlevel that may well have been cheese, the dashing red glyph (applied by squeeze bottle) on top.
Except for the chili sauce, however, the flavor and texture was only marginally distinct from that styrofoam caddy (which I left intact). The crust might have been baked from a rice-flour dough, or rice and wheat, but I lacked enough Thai to ask, and the vendor spoke no English. Since my visit, he seems to have moved on to some other line of business; I can't find any inkling of his pizza online.
Street cart pizza
Khlong Toei Market, Bangkok
(From a December 2006 visit)