Now, while the typical way of serving al pastor is definitely not paleo, the pork itself is perfectly within the limits of a paleo diet and can be enjoyed by itself or on top of fresh greens as a "taco" salad. I based this recipe off of one I found on tasty.co and it is the closest I've been able to come to recreating that classic Southern California staple: taco truck al pastor.
Equipment
gallon ziploc or tupperware with lid for marinating pork
4 or 6 wooden skewers
baking sheet or casserole dish (optional: line with foil for easy cleanup - the oven cooks off A LOT of fat from the pork)
small saute pan (cast iron recommended)
Ingredients
3-5 lb. BONELESS pork shoulder
3 tbsp achiote powder (or paste)*
2 tbsp chili powder
1 tbsp garlic powder
1 tbsp dried oregano
1 tbsp cumin
1 tbsp salt
1 tbsp pepper
3/4 cup white vinegar
1 cup pineapple juice**
1 fresh pineapple
*achiote: I have trouble finding this at some supermarkets so if you have a Latin grocery store in your area, check there. You MIGHT also have luck in the latin aisle of your neighborhood supermarket
**I use frozen pineapple juice concentrate in 11.5oz containers. Add 2 oz to a cup and fill the rest with water
Directions
1. Using a very sharp knife, slice the pork shoulder into 1/4 inch slices. I find it helps if the pork is mostly defrosted or at least kept in the fridge immediately before slicing - the pork is much easier to cut while cold.
2. Mix all of the ingredients together (except the fresh pineapple) and make sure it is free of lumps before adding the pork slices. Marinate anywhere from 3 hours to overnight.
3. Preheat the oven to 350F. Skin the pineapple and cut it into 1-inch rounds (you will need at least 6 slices). Make 2 stacks of 2 slices of pineapple in the bottom of the baking sheet. Depending on the size of the skewers, stick 2 to 3 into each stack of pineapple - pointy side up.
4. Remove the pork from the fridge and stack the slices onto the pineapple, piercing the middle of each pork slice with the skewers. I find it best to alternate stacks with each slice, making sure to put the largest slices at the bottom of each stack and the smallest slices at the top. Finish each stack with one more slice of pineapple and push down to compress the pork into a denser stack (this will help retain flavor during baking).
5. Bake for 3 hours, checking every now and then to make sure the towers haven't fallen over. This tends to happen and I have tried various engineering feats, none of which work 100% of the time. My most frequent method is to arrange the racks in the oven so that the top of the skewers poke through the top rack while the bottom rack holds the baking sheet. The towers always tend to lean a little bit, so try to make them lean against the center rail of the top rack.
6. Remove the pork from the oven and let rest a few minutes before carefully removing the pork from the skewers with your carving knife. Chop the pork and 3 of the 4 slices of pineapple from the bottom of the stacks (the top ones are too dry). Mix the pork and pineapple thoroughly then add the amount you want to serve into a small saute pan (I use cast iron) over medium heat. Stir frequently until the pork has cooked off a lot more fat and the edges start to char. Set the pork on paper towels to wick away more of the fat (good lord, there's so much fat)
7. non-paleo serving suggestion: serve with warmed tortillas, chopped white onion, cilantro and squeezes of lime
This is my favorite new culinary discovery and I keep a steady supply of pork shoulders in my freezer just for this dish. Enjoy!