I entered this recipe into a grilling contest recently. Eating the pork adobo tacos at La Carreta was my inspiration. I marinate the pork in an adobo/pineapple juice mixture. If you can't find canned adobo sauce, then buy chipotles in adobo sauce and just use the sauce. I freeze any leftover chipotles and adobo in an ice tray (from the dollar store) for later use.
Grilled Adobo Pork Skewers
2 pounds pork loin roast, cut in 2 inch cubes
1-20 ounce can pineapple chunks in juice, reserve 1/4 cup juice
4 tablespoons adobo sauce (not the chipotles)
1 tablespoon chile powder
1 teaspoon garlic powder
fresh avocado, diced
Mix the adobo sauce, 1/4 cup pineapple juice, chile powder, and garlic powder in a large zip loc bag. Add the pork cubes to the adobo mixture. Marinate in the refrigerator for 4 hours or longer. After marinating, put the pork on skewers alternating with the pineapple chunks. Grill 13-15 minutes or until the pork is cooked through.