Ingredients:
Boil Ancho peppers in a pot or pan of water for about 5 minutes. Remove the pepper and place them in a blender with 1/2 cup water, used to boil chilis, Serranos, and 4 garlic cloves. Juice oranges, limes, and pineapple into a large bowl along with one beer. Add coriander, cumin, smoked paprika, Mexican oregano, cayenne pepper, and pepper.
Pour in the ancho mixture, sliced green onion, chopped cilantro, and sliced shallot into the bowl and stir. Place the flap meat into the bowl and place in the fridge overnight. Heat your grill over medium high heat and cook for about 5-7 minutes on each side. This could be used for tacos or served with rice and beans and toppings of your choice. Serve and enjoy!
Side Note: Do not use fresh pineapple, must use pasteurized/canned, due to natural enzymes already in the meat marinade used to tenderize meat.