Let me explain a little about gizzard. Filipinos call it balunbalunan or balumbalunan. Either way is acceptable.
Gizzard is an organ found in the lower stomach of birds that aids in the grinding of their food. It tends to be tough and chewy that it is best braised like in adobo where it gets cooked for a longer period of time.
1 1/2 pounds pork belly, cubed
1 1/2 pounds chicken, cut into serving pieces
3 to 4 pieces dry bay leaves
2 teaspoons whole black peppercorns
1 head garlic, slightly crushed
3/4 cup vinegar
1 tablespoon oyster sauce
3 tablespoons brown sugar
1 cup water
3/4 to 1 cup soy sauce
Salt to taste
3 tablespoons cooking oil
1/2 pound chicken hearts
1/2 pound chicken gizzards
8 hard-boiled eggs, peeled
1. Heat oil in a pan and saute the garlic.
2. Add the pork, chicken, hearts & gizzards to the pan. Cook for 5 minutes.
3. Add the soy sauce, whole peppercorns, bay leaves, oyster sauce and water. Bring to a boil and simmer until the meats are tender.
4. Add the sugar and stir.
5. Pour in vinegar and let boil. Simmer until most of the liquid evaporates.
6. Add salt to taste.
7. I prefer to brown the adobo in the oven instead of pan frying to avoid oil splatter. So transfer the adobo to an ovenproof dish and broil until nicely browned.
8. Add the hard-boiled eggs. Stir to incorporate with sauce.
9. Garnish with sliced tomatoes.
10. Serve hot with rice and the adobo sauce.