Cut the okra in pieces about 1 inch in length.
Soak the tamarind and extract the pulp.
Chop onion and green chillies.
Heat oil and add mustard seeds. Wait for it to crackle and then add onions to it.
Saute onions until translucent.
Add curry leaves and all powders.
Mix in the okra and saute on a slow flame for 5 minutes.
Add tamarind and water to thin the gravy, boil until the okra is cooked.
Simmer on a slow fire for 10 minutes.