1. Wash, pat dry and cut the okra into 1 inch pieces.
2. Heat the groundnut oil in a kadhai and deep fry the okra on medium heat till crisp, about 5-6 minutes.
3. Drain and reserve the oil.
4. Put the cashew nuts and the coconut in a blender, add coconut milk and make a fine paste.
5. Heat 75 ml of the reserved oil.
6. Add cumin and mustard seeds, urad daal, whole red chillies and the curry leaves.
7. Saute over medium heat till the seeds begin to crackle.
8. Add onions. Saute till golden brown.
9. Stir in the tomatoes, then add red chilli powder, turmeric, coriander and salt.
10. Keep stirring till the fat surfaces.
11. Reduce the flame, add the coconut paste and stir again for 2 minutes.
12. Remove from the fire and add yogurt.
13. Stir, add 400 ml/1 2/3 cups water.
14. Return to heat and begin to boil. Simmer.
15. Add the deep fried okra and cook till gravy seeps in.
16. Transfer to a shallow dish and serve with boiled rice.