Pork Ribs in Mole Verde

4 pounds country-style pork spareribs
1/2 white onion, sliced
2 cloves garlic, peeled
8 peppercorns
1 tablespoon salt
Water

Cut the meat into serving pieces. Put them into a pot with onion, garlic, peppercorns and salt. Cover with water, then bring to a boil. Lower the heat and simmer until the pork is tender, at least 25 minutes.