Tacos Al Pastor (pork tacos)

• Art loved the Tacos Al Pastor when we were in Mexico. After trying many recipes (including Mom's delicious one), this is what we have come up with as our favorite. Since we love our shredded beef tacos, we like the grilled pork from this recipe.
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• 1 large white onion, halved
• 2 pineapples, peeled, cut crosswise into 1/2-inch-thick rounds
• 1/2 cup fresh orange juice
• 1/4 cup distilled white vinegar
• 1/4 cup guajillo chile powder (we have only found the guajillo chiles dried and have had to make our own powder)
• 3 garlic cloves, halved
• 2 teaspoons sea salt
• 1 teaspoon dried oregano (preferably Mexican)
• 1/2 teaspoon ground cumin
• 1 large or 3 small chipotle chiles and 1-1/2 to 2-1/2 teaspoons adobo from canned chipotle chiles in adobo
• 1 2-1/2 to 3 pound boneless pork loin, cut into 1/4 inch slices
• 1 cup chopped fresh cilantro
• Corn tortillas (again, we like the ones from Mexican markets best)
• Lime wedges

Coarsely chop 1 onion half. Coarsely chop 2 pineapple rounds, discarding core; cover and chill remaining pineapple. Place chopped onion and chopped pineapple in blender. Add orange juice and next 7 ingredients; puree marinade until smooth. Place pork in large resealable plastic bag. Add marinade and seal bag, releasing excess air. Turn to coat. Chill at least 4 hours and up to 1 day. Don't marinate for longer than 1 day, as the pork starts to get mushy.

Prepare barbecue (medium-high heat). Grill remaining pineapple until warm and slightly charred, 4 to 6 minutes per side. Grill pork with some marinade still clinging 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, discarding cores, place on platter or in bowl. Chop pork. Transfer to platter.

Meanwhile, finely chop remaining onion half and place in medium bowl. Chop cilantro and place in bowl. Heat tortillas until warm. Serve pork, pineapple, onion, cilantro, and lime wedges on two warm corn torillas.

To make your own guajillo chile powder, finely grind about 6 large dried seeded guajillo chiles in a spice mill to yield about 1/4 cup powder.