Procedure: Using a pilón (mortar and pestle), mash the garlic cloves and salt into a paste.
Mix in the pepper and oregano. Stir in the olive oil and vinegar. Set the marinade aside.
Cut the pork into 1-inch cubes.
Cover the pork pieces with the marinade and let set in the refrigerator for about 20 minutes.
Skewer the pork pieces and grill the kabobs for about eight minutes, turning occasionally for even grilling.
Tip: If you use wooden skewers, soak them in water while the pork is marinating.