Ingredients

2 1/2-to 3-pound (1.25 kilos) boneless pork loin, cut into 1/2-inch (1 cm) slices
1/2 cup fresh orange juice
2 tablespoons achiote paste
1/4 cup distilled white vinegar
1 tablespoon guajillo chili powder
1 tablespoon garlic powder
2 teaspoons coarse kosher salt
1 teaspoon dried oregano (preferably Mexican)
1 teaspoon ground cumin
1 or 2 small chipotle chiles and 2 teaspoons adobo sauce from canned chipotle chiles in adobo
1/4 cup chopped fresh cilantro (coriander)
1 small red onion, diced
1 large can pineapple slices, drained
Corn tortillas

Instructions

1.Cut pork loin into ½ inch slices. (It may help to place pork into the freezer for 15 minutes to aid in achieving thin cuts)
2.In a blender, add orange juice and next 8 ingredients (through chipotle chiles and sauce). Blend until well combined.
3.Place pork in large resealable plastic bag. Add marinade and seal bag, releasing excess air. Mix to coat. Chill at least 4 hours and up to 1 day.
4.Meanwhile, finely chop red onion and place in a bowl. Add cilantro and toss to combine.
5.Prepare barbecue (medium-high heat).
6.Grill pineapple until warm and slightly charred, 4 to 6 minutes per side.
7.Grill pork until slightly charred and cooked through, 2 to 4 minutes per side. Transfer pineapple and pork to work surface; chop pineapple into 1/2-inch cubes. Chop pork.
8.Grill tortillas until warm and slightly charred, about 10 seconds per side.
9.Serve hot; layering the pork, pineapple and onion/cilantro mix on a tortilla.
10.NOTE: Alternatively, on a foil lined baking tray broil the pork in a 400˚F (200˚C) oven until slightly charred and cooked through, about 10 minutes. Char pineapples in a hot, dry skillet, 2-3 minutes per side.