Put tilapia in a pot and add salt. Add the garlic, onions and ginger. Then pour the vinegar.
Turn on heat and bring to a boil. Boil for 5 minutes and cover.
After 5 minutes, add pechay put on top of the fish. Add finger chilies then pour the coconut milk.
Cover and continue boiling until the sauce is reduce to half or until thick.
Season with ground black pepper if desired. Serve hot.