Mussel fry-ups aren't the only dishes on offer at this stall, just the ones with the fastest turnover.
A nearly constant turnover, in fact, from the unsmiling three-person crew; it wasn't perfectly clear whether fresh ingredients were being deposited in the large tilted frypan in response to a particular order or in anticipation of the next. The mussels in this workmanlike hoy thod (35 baht, about $1.10 at the time) were bound together with a crispy batter made from egg and (typically) tapioca flour. Underneath was a substantial bed of bean sprouts; the chili sauce was thin, not too hot.
Note, too, the colored tips on the fork and spoon. At one end of the expansive Aw Taw Gaw wet market (sometimes transliterated Aw Taw Kaw or Or Tor Kor) is a section for prepared-food vendors like this one, with a common seating area. The color coding may be intended to help return the utensils to the proper stall, or, at least, to discourage light-fingered diners from walking away with the flatware.
Hoy thod vendor
Aw Taw Gaw market, stall 11/40, Bangkok