Put a heavy bottom pan on the heat and add mustard oil, let it heat up. Next, add the gram flour and roast it for a few seconds until fragrant, remove from heat, and set aside.
In a bowl take hung curd, add ginger garlic paste, Garam Masala, red chili powder, Kasuri Methi, coriander powder, salt, pepper powder, and lime juice, and give it a nice whisk.
Next, add in the prepared oil and gram flour mixture and mix everything properly.
Make deep gashes in the chicken and add them into the mixture. Add a few drops of red food color. (optional)
Rub and coat the chicken properly in the marinade and let it rest for a minimum of 6 hours.
Preheat the air fryer for 5 minutes at 180-degree C / 350 degrees F. line the basket with aluminum foil and put the marinated chicken in it. Brush some butter on the top. Cook for 10 minutes on one side then turn and cook for another 7 -8 minutes. Repeat with the rest of the chicken.
Serve hot with lime wedges and onions, sprinkled with Chaat Masala.
Plate, serve, and enjoy!