I'm making a version of Cochinita Pibil tomorrow. I just made the Achiote paste and dumped in a zip lock bag with big chunks of pork butt. No sour oranges in my grocery, so I juiced two navel oranges and four limes for close approximation.
I have done the banana leaves (for the Yucatan fish taco version), but find it a lot of bother. What I do is build a roaring hot charcoal fire and sear the pork chunks, then sear the onion slices, then sear the anaheim chiles, then sear the roma tomatoes. Then, cut up all the veggies and dump them in a big foil pan with the pork chunks and the marinade. This could be covered with foil and cooked like a pot roast in the over or on Weber kettle. I'm going to leave it uncovered and slow cook it at 250 degrees along with some baby back ribs and beef short ribs. I'll put it on the top grate so I can stir the pork chunks around from time to time. I'll cook it 'til it's pulled pork tender, however long that takes. I'm guessing 4 to 6 hours.
It's awesome. A Yucatan pork stew but with the added flavors of the charcoal seared veggies and pork chunks.