This is another popular North Indian okra recipe, provided by my wife, Jyotsna Kochhar.
Fresh okra is often available at Indian or Asian grocery stores.
You may have to look there for the mango powder, too. The other ingredients are commonly available at any supermarket. This is best as a side dish, probably better with breads than with rice. Wash okra, let dry thoroughly, or pat dry with paper towels. Chop ginger and garlic into small pieces.