Mix the yogurt with fresh chopped mint, salt and pepper. It will be added as an extra.
Heat the fat and fry the chicken well in it. Add the onions and fry until translucent. Then add the garlic, chilli, coriander seeds, oregano, sugar, tomato paste and tomatoes and stew a little, then add the hot water and bring everything back to the boil. Cover the saucepan and cook for 20 minutes, stirring occasionally.
Now add the potato pieces and bring to the boil. Cover the pot and cook for another 20 minutes.
Now add the okra or zucchini pieces and the lemon juice, stir well, season if necessary and simmer for another 10 minutes. Season to taste and serve with the yogurt.