1. Rinse the okra, drain them, and clean them. With a small sharp knife, remove the cap from their heads, without removing it entirely.
2. Turn the knife and trim them conically. Be careful because if you remove their heads completely, the okra will open up. Place them in a bowl and pour the vinegar over them. Sprinkle with a little salt and mix. Set them aside for about ½ hour.
3. In a pan, add the olive oil and sauté the onion until golden. Add the garlic and stir for a few seconds. Add the tomato paste and rub it against the bottom of the pot until it releases its aromas.
4. Add the grated tomatoes, a little salt, and simmer for 5 minutes. In a baking dish, place the chicken and potatoes. Season with salt. Add the okra and tomato sauce on top.
5. Add the water. Cover the baking dish with its lid, or with parchment paper and aluminum foil. Bake in a preheated oven at 200°C for 1 ½ hours. Uncover, carefully stir the dish, and continue baking at 180°C for ½ hour or until the dish is golden brown.
