Slit the okra lengthways down one side without slicing them in two.
Heat the oil in a large, heavy-based pan over medium heat, add the cumin seeds, and stir-fry for about 1 minute, or until they start to splutter. Add the onions, ginger, and garlic and stir-fry for about 5 minutes.
Add the okra and fry for a further 15 minutes. Now add all the spices and the tomatoes, then season with salt and mix well.
Reduce the heat, cover, and simmer for about 15 minutes, stirring occasionally to stop the okra from sticking to the pan. Remove from the heat and keep covered until ready to serve.