Step 1

Prepare the marinade. In a medium saucepan, melt butter over medium heat. Stir in the onions and garlic and cook, stirring occasionally, for 2-3 minutes or until fragrant. Add the chicken stock, ancho chili peppers, and chipotle chili peppers with adobo sauce to the pan and bring to a boil. Cook the peppers and onions in the stock for 4-5 minutes. Reduce the heat to low and stir in the achiote paste, cumin, Mexican oregano, salt, sugar, and vinegar. Simmer the marinade for 4-5 more minutes.

Step 2

Blend the marinade. Turn off the heat. Carefully remove the stems from the ancho chili peppers and place in a blender jar. Transfer the remaining contents of the pan to the blender jar, close the lid, and blend until completely smooth. Allow to cool to at least room temperature. Marinade can be made a day in advance, if needed.

Step 3

Marinate the pork. Place your sliced pork shoulder in a large glass bowl or gallon sized zip top bag. Pour the cooled marinade over the pork and massage everything together to thoroughly coat each piece of pork. Cover with plastic wrap or seal tightly in the bag and refrigerate for at least 4 hours, or up to 24 hours.

Step 4

Preheat your smoker. Preheat your smoker to 275 degrees F using your favorite hardwood. I used cherry wood for this cook, but oak, maple, or apple would all work well.

Step 5

Assemble the meat on the spit. Using a vertical skewer or rotisserie attachment, slide the meat onto the skewer one piece at a time, keeping the meat even around the edges and sides so there aren't any large pieces of meat overhanging any other.

Step 6

Smoke the al pastor. Place the assembled al pastor meat on the grill grates and close the lid. Smoke for about 4 hours, or until the internal temperature of the pork in the thickest portion reads 145 degrees F. If using a vertical skewer, baste the outside of the meat with the drippings from the pan every 30 minutes during the cooking process (skip this step if cooking on a rotisserie, it will self-baste).

Step 7

Grill the pineapple. During the last 30 minutes of smoking, place the pineapple wedges on the grill next to the al pastor. Close the lid and cook, flipping once after 15 minutes.

Step 8

Slice and serve. Remove the al pastor and the pineapple from the smoker. Top the al pastor skewer with the pineapple top and chop up the grilled pineapple. Slice the al pastor from the spit with a sharp knife, using a light sawing motion to remove small, bite-sized pieces. Place the meat and pineapple in taco shells and top with fresh cilantro, diced onion, and a squeeze of fresh lime.