In a large bowl, combine minced garlic, olive oil, orange juice, lime juice, ground cumin, dried oregano, salt, black pepper, and optional smoked paprika. Whisk these ingredients together until well blended.

Place the pork shoulder into a resealable bag or a deep dish, ensuring it has enough space for the marinade. Pour the prepared marinade over the pork, making sure it is thoroughly coated. Seal the bag tightly or cover the dish, then refrigerate for at least 4 hours, preferably overnight.

Preheat your oven to 325°F (165°C). This lower temperature allows the pork to roast gently.

Remove the marinated pork from the refrigerator. Place the pork shoulder into a roasting pan, fat side up. Roast in the preheated oven for 3 to 4 hours, basting occasionally with the reserved marinade.

Once the pork has finished roasting, let it rest for at least 15 minutes before slicing or shredding.