Wash and drain gherkins. Cut lenghtwise into 8 to 10 pieces. Heat oil. Add mustard se3eds. When they crackle add gherkins and saute. Cover and cook over a slow fire(no water should be added) till tender. Stir now and then. Remove lid. Add salt, turmeric, cumin powder and chilli powder. Mix well. Cook for a further 5 mins. Add sugar. Mix well and remove.