Rinse Bhindi in running water and wipe with kitchen towel. Leave it until it is dry for at least 1 hours. This will help in avoiding Bhindi becoming sticky while cooking.
Cut the Bhindi into one inch pieces.
Heat 2 tbsp oil in a pan and stir fry Bhindi with some salt and pinch of turmeric powder until it is tender and slightly golden color.
Achari masala: 1 tsp cumin seeds, 1 tsp mustard seeds, 1 tsp Nigella seeds (Kalonji), 1 tsp Fennel seeds, 1/2 tsp Fenugreek ( methi)seeds. Dry roast all the spices in a pan for 2 to 3 min at low to medium heat till aromatic. Grind the spices in a grinder until powdered. Keep aside.
Heat 5 tbsp of oil in a pan at medium heat, add cumin seeds and once it crackles, add onion and little bit of salt and saute it for 1 minute. Add ginger garlic paste and saute it till golden brown color.
Add tomato, saute it until tomato gets mushy. Add 1 tbsp achaari masala powder, coriander-cumin powder, turmeric powder, amchoor powder, chili powder and pepper powder. saute the masala for 2 more minutes.
Add 1/2 cup of water and bring it to boil.
Add the Bhindi and cook for 1 more minute. Stir slowly so that Bhindi does not break.