I finally had a chance to try the soup dumplings hidden as "steamed buns" on Taiwan Cafe's menu (see 9lives thread below). The dish is properly called some variation of "Xiao Long Tang Bao". Taiwan Cafe's version is fairly utilitarian compared to the mythical dumplings served at Taipei's famous Ding Tai Fong restaurant, which are about half the size and come in more different flavors and shapes. But good enough for Boston, so I'm not complaining. One bite and the broth explodes into your mouth and, if you are not careful, all over your face, shirt and pants (rather dangerous when piping hot!). We took a couple home, and it is clear that I was wrong about ice cubes being the trick. Once they've cooled, you can see the meatball was originally encased in jelly, which melts when cooked.
Also had the often-recommended eggplant and basil, which is tasty and impossibly huge for two, but could use a bit more basil and hot peppers (I love basil to distraction!). The salt and pepper shrimp were big, sweet and juicy, but also could have been a little spicier.
I recommend the stewed minced pork on rice with chopped pickled syun tsai (mustard?) and pickled white radish. Nothing fancy, but true Taiwanese comfort food.
I can't believe the reviewer at Boston.citysearch.com gives this place a 5/10 for food. Tasty, authentic, fast, cheap...who cares if it is a hole in the wall?