This week's sandwich: meatball!
The meatball was coarsely ground pork, flavored with garlic, onion, and (I think) a touch of sesame oil, and served warm. Very savory and flavorful. The outside edges had a nice chewy char to them, as if they'd been broiled or fried until brown. The flavor and texture reminded me a bit of Cantonese steamed meatloaf.
The only catch was, that of all the fillings so far, this was the only one that didn't harmonize well with the other components--in particular, the flavor of the meat seemed to clash with the sweetness of the pickled veggies.
So, it wasn't my favorite so far--but if someone were to hand me another one I'd definitely eat it.
Still working up the nerve to try the infamous shredded pork skin sandwich...