Marinated in spiced yoghurt, Kashmiri chillies, and garlic, then roasted over roaring tandoor charcoal embers with charred edges.
Cut the idlis into thick fingers and pat them dry.
Whisk the yogurt with tandoori masala, Kashmiri chili powder, ginger-garlic paste, and salt; coat the idli fingers and rest 15 minutes.
Thread the marinated idli fingers onto skewers.
Grill over high heat, basting with mustard oil, until crisp and charred at the edges.
Dust with chaat masala and serve hot with green chutney.