I finally had some time to hunt this place down and i was not dissapointed.
Their menu is very authentic, I had a hard time deciding what to choose. I know I have to come back just to try the things I didn't have last time!
Don't forget to order the Orchata with your meal, IT'S HUGE!

I echo all comments above. Some of the best Mexican food in Seattle But word of warning: no beer, no margaritas, nada. I have heard that the owner is dedicated to AA (and good on that) so it's not likely to change.

The Quetzal, as the menu at El Quetzal will tell you, is a Central American bird that to the Aztecs was a representation of life and freedom. El Quetzal itself is a small, happy little restaurant on Beacon Hill celebrating life through authentic homemade Mexican food. As you look around you will notice that the clientele is mostly Mexican, and this is a good sign. The nice lady working the counter brings you warm salty corn chips and cactus salsa and hands you a gigantic menu full of breakfast and lunch items. Not listed on the menu is horchata, but be sure to ask for it anyway; they have it, the thick, milky variety, not the watered down stuff usually found in taquerias. The breakfast items consist mainly of eggs and sound very substantial. They also have the usual assortment of tacos, made with “double soft” tortillas and priced at $1.50 each. I, however, didn’t try any of these and instead went straight for the tortas. El Quetzal’s tortas, or Mexican sandwiches, are described on the menu as “gigante”: this is not a misnomer. My torta chilanga, made with breaded flank steak, arrived taking up the entire dinner plate. The bread it was served on was light, crusty, soft and warm on the inside, like the very best French baguette. It was stuffed with tomato, onion, avocado, mozzarella, and chipotle sauce, which gave it a nice hint of spice. God but it was good.

This is some of the best mexican food in seattle. the place is a bit of a hole in the wall (intended as a compliment) and has a family-run feel to it. in fact, it feels like the whole family (including kids) are in the kitchen helping ouot. prices are reasonable, sauces are excellent. if you like the fare from taco trucks and the few taco busses around town -- but would like to sit down a have a beer with the meal -- el quetzal is the real deal.