Start with 2-3 lbs of Pork butt or shoulder (they're the same thing) and set it in a crock pot. Next, in a bowl, mix the juice of a couple oranges, a couple tablespoons of cumin, and about a tablespoon of annatto. I didn't know what annatto was two weeks ago. It's a berry that adds a nice sweetness to these types of stewed dishes. A little goes a long way. It can be tough to find, but if your grocer has a decent Mexican spices section, you should be able to find it. Blend those together with a hand blender or whisk. Combine all of that in a crock pot with the meat, a few cloves of garlic and a chopped onion and put it on high for five or six hours. I like to take the lid off after a few hours to let the water evaporate and allow the juices to thicken. It will fall apart after about five hours and that's how you know it's ready.
I'll eat this wrapped up in Boston lettuce. I've found Boston lettuce to be the perfect vessel for almost anything I would normally eat with a tortilla or any other type of bread. I like to make individual bite sized wraps with some tomato, cilanro, lime juice, and my new favorite condiment: Labna. Labna isn't strictly Paleo, but I've found it to be a good alternative to sour cream as it adds the same flavor, but has some healthful probiotic cultures as well. I generally try to keep my dairy extremely limited, but if you like to indulge occasionally, this is one good option.