Add the onions, tomatoes, parsley and chives, and sauté well.
Pour in the hot water and simmer over low heat for about 30 minutes, until the chicken is tender.
Whisk the flour smooth with a little cold water, add it to the sauce along with the vinegar, and simmer for a few minutes until it thickens.
The traditional recipe uses a little chicken blood at this point for the sauce's characteristic dark color - this version leaves it out; only the tomato, flour and vinegar give the deep color and flavor.
Serve with corn porridge (angu) or cooked rice and steamed okra.