In Chicago I fell in love with a certain kind of taco they made there: two soft corn tortillas, pork "al pastor", onions, and cilantro, with a lime squeezed over the top - that's it. No cheese or tomatoes or lettuce or any of that other garbage. I haven't found quite the same thing here yet, so I thought I'd try to make them myself.
Mark at eatingcleveland.com recently posted a yummy sounding recipe for pork carnitas. I made the pork Sunday and I'll use it to make tacos Wednesday. It was easy, and went pretty much the way Mark said it would; I'll second his recommendation to use a heavy pan or Dutch oven with a heavy lid. I think my light-lidded pan allowed too much steam to escape, as there wasn't much liquid left at the end. But, the pork tasted fantastic: it had a little tang from the limes, a little heat from the anchos, and amazing flavor from the cumin that I ground fresh that day.
Now, carnitas is not the same as al pastor. The flavor in al pastor comes from adobo, one of my favorite Mexican sauces. You can get adobo concentrate in little jars in most grocery stores. Al pastor meat (usually pork, as is carnitas) is made by layering the meat onto a spit basted with the sauce and sliced off--just like gyro meat!
This gives me an opportunity to give a shout out to Falafel Cafe in University Circle, who make the best gyros I've had in Cleveland. Their french fries are on the greasy side, but I keep coming back. And I'll let you know how the tacos turn out Wednesday.
P.S. Wondering where on earth you can get odd spices like whole cumin seeds? Look no further than Penzeys. I've been ordering from them through the mail since the late 90s, and there's a branch on the East Side of Clevleand.