Mix all the dry masalas, add them to ladies’ fingers and steam. The colour should remain green (takes about 10 minutes). Dry mango powder prevents the ladies’ fingers from becoming sticky.
Roast the onion in a kadhai (or heavy bottomed stainless-steel pan) on high heat. When it browns, add tomatoes and sauté. Cook for a minute or two, until the tomatoes start releasing water. Add the steamed ladies’ finger and stir well, so that the onion tomato mixture coats them. Cook until heated through. Garnish with coriander leaves. If you want the bhindi to be crisp, bake in a preheated oven at 200 °C for 10 minutes after steaming. Serve hot.