Slice the onion into eighths and then chop the slices in half. Separate onion pieces and set aside. Slice the limes into eighths and set aside.
Chop the pork into 1 1/2 inch cubes and set aside.
In a sealable bowl or container with a lid, combine and mix 1/2 teaspoon vegetable oil, salt, pepper, coriander, and cumin.
To the same bowl, add the pork and mix to coat all surfaces. Let pork marinate for 20 minutes.
To the bowl, mix in the onion, brown sugar, soy sauce, and ginger.
Seal the mixture. Place it in the refrigerator and let it marinate for at least one hour. For more flavorful pork, let the mixture marinate overnight.
Set a grill on high heat and lightly coat with vegetable oil.
Skewer the pork cubes and onions in desired arrangement.
Place the skewers on the grill and brush with the remaining marinade.
Cook, rotating skewers occasionally, for 15 minutes or until the pork is thoroughly cooked.
Discard the remaining marinade.
Serve hot with lime wedges.
