In a bowl take besan, chilli pd, turmeric, salt, black salt, chat masala, ajwain, 1tsp hot oil,salt n mix and make a batter
In another bowl take chopped onion, tomatoo, chilli,salt, mayonise, coriander leaves and mix
Take bread slice aaply butter and spread mayo mixture
Cover with another bread slice
Dip into besan batter
Shalliw fry on grilled tawa
Apply oil or butter
Cook from both sides
Cut into triangle shape
Serve with ketchup or with green chutney