Preheat your oven to 325 degrees.
Pulverize the 5 spices (annantto, cumin, peppercorns, allspice, and cloves) into a fine powder using a spice grinder.
In a blender goes the chilies, orange juice, vinegar, salt, and spice powder. Blend well, the smoother the better. Now add the juice of 5 lemons and tequila to the blender. Pulse once then set aside.
Grab a large zip lock bag (a large bowl works too) and stuff the bag with the cubes of pork. Pour the contents from the blender over the pork. Seal up the bag and give the ingredients a good mix. Be sure the pork is well coated.
Line a 9x13 baking dish with banana leaves. Dump the pork on top of the leaves, then cover the pork with more banana leaves. Now wrap the top of the pan with tin foil. You don't want any steam escaping the pan, it's how the pork will be cooked!
Put the baking dish into the oven and slow cook for 4 hours. The meat should be extremely tender. So tender you can shred the meat with the back of a spoon. If the meat seems kind of tough, continue roasting it in the oven. Once the meat is tender shred it using two forks.
Serve over rice, or even in tacos!