In a medium bowl, mix oil, lemon juice, garlic, and spices. Add the pork cubes and mix by hand until all the pork is coated. Cover and marinade for at least 1 hour in the refrigerator (up to overnight).
When you are ready to cook your pork, preheat your grill to a medium heat, roughly 350F. (You should be able to hold your hand 4-5 inches above the cooking grate for 5-7 seconds).
Soak the wooden skewers in water for 1 minute. Then, thread the marinated pork cubes onto the skewers.
Grill the skewers until the pork pieces are firm and cooked through, turning once, roughly 2-3 minutes per side. (The cooking time will depend on the heat of your grill.)
Serve the skewers with lemon wedge and mojo picon as a hot or cold appetizer.