Dry-fry the cumin, coriander and mustard seeds in a
small frying pan until they start to pop and give off a
smoky aroma. Remove from the heat and grind to form a
rough powder.
Heat the oil in a saucepan, add the onion,
garlic and ginger, and fry over a moderate heat for 10
minutes until golden.
Stir in the tomatoes, cover and
continue to cook for a further 10 minutes. Add the
roasted spices, turmeric and chili powder, okra and
stock.
Bring to the boil, cover and simmer over a very
low heat for 20 minutes, until the okra is tender.
Stir
in the coriander and season to taste with salt and
pepper. Serve hot.