Mix the juice, oil, minced garlic, cumin, chili powder, smoked paprika, dried oregano, salt, and pepper in a bowl. This mixture will be your marinade. Note that you can choose your type of juice from the list I mentioned above.
Cut the Machitos into smaller pieces so that you can handle them more easily. Place the machitos into the marinade bowl or in a plastic zipper bag along with the marinade.
Cover the bowl, or close the bag, respectively. Make sure the machitos and the marinade are well mixed and equally distributed through whichever container you use. Refrigerate the machitos and let them marinate for at least two hours.
Grilling Machitos
Heat a grill or a large skillet over medium-high heat. Remove the machitos from the marinade, and allow for the excess liquid to drip off.
Grill or pan-fry the machitos for about 4-5 minutes per side or until they are cooked through and slightly crispy on the edges.
Preparing Tacos
While you cook the Machitos, warm up the taco shells in the oven. Place a few slices of machitos and top with chopped cilantro, diced onions, and sauce. Squeeze a lime wedge over the filling for a zesty kick.
Bring your non-sticking pan to medium heat and crisp up the tortillas from both sides.