Cut the paneer into 1.5”x1.5” cubes. Sprinkle salt and chilly powder and keep paneer in a warm place for 15 minutes. If paneer releases any water remove it.
In a separate bowl whisk together hing curd, salt, ginger garlic paste, and chopped coriander. In a separate pan heat mustard oil to high heat. Immediately add ajwain, green chili, and ginger, and stir for a few seconds. Turn off the heat and add besan and turmeric. Stir for a minute or till besan turns into a light brown color. Immediately add this tempering to the curd marinade and whisk it.
Apply this marinade to the paneer, diced onions, and peppers. Using wooden skewers, alternatively skewer paneer cube, onion & pepper cube and repeat. Do this till all of the paneer is used. Heat a grill pan & lightly oil it. Place the skewer and cook on all sides till it gets good colour. Remove sprinkle chaat masala and serve.