I have to make an amendment to this review -- El Portal is no longer around, so I can no longer suggest going there. I think the restaurant suffered from a weak location and not enough foot traffic, making them go under fairly quickly. Such a shame!
While not a conventional "small plates" restaurant, El Portal can easily qualify for this description. When I went with my boyfriend we shared everything we ordered and it was all absolutely delicious -- the guacamole is made at your table, and everything else we ordered was fabulous, too. I would suggest going here with a group of friends and ordering margaritas -- you will leave slightly drunk and with very happy stomaches. The bartender is great, the staff is exceptionally friendly, and, as I said, the food is very good (which is a rarity here in Seattle -- good Mexican food.)