Begin by cutting the paneer into large cubes, approximately 2 inches in size. Peel and chop the onion into square pieces that match the size of the paneer. Remove the stem and core from the bell pepper, then cut it into pieces similar in size to the onion.

Using a mortar and pestle, pound the green chillies into a coarse paste. If you're making ginger garlic paste from scratch, you can combine it with the green chillies while pounding.

In a pan over low heat, dry roast the besan for 4-5 minutes until it loses its raw smell, being careful not to let it burn.

If you find mustard oil's aroma too strong, you can warm it until it shimmers, then let it cool before adding it to the marinade. This will mellow its flavor.

In a large bowl, combine the Greek yogurt, ginger-garlic paste, green chilli paste, and all the ground spices: red chilli powder, coriander powder, garam masala, chaat masala, amchoor, cardamom powder, nutmeg, roasted besan, kasuri methi, and mustard oil. Whisk the mixture until it is smooth and thick.

For enhanced flavor, let the marinade sit in the fridge for 1-2 hours if time permits. Add the paneer cubes to the marinade and gently mix with a spatula or your hands, being careful not to break the paneer. Cover and let it marinate for 1-2 hours, or up to 6-8 hours. If using soft paneer, limit the marination to 2-3 hours.

Do not marinate the vegetables, as they will release water due to the salt. Instead, reserve 3-4 tablespoons of the marinade to toss with the bell pepper and onion just before cooking, about 6-8 minutes prior.

Brush the skewers with oil before threading the marinated paneer, bell pepper, and onion onto them. If using wooden skewers, soak them in water for 30 minutes to prevent burning.

When skewering the paneer, position the flattest side facing up to ensure even cooking. Preheat your air fryer to 370°F for 2 minutes.

Arrange 4-5 skewers in a single layer in the air fryer basket, ensuring they do not touch. Spray or brush with avocado oil or ghee for cooking. Line the basket with a perforated sheet for easy cleanup.

Cook the skewers for 4-5 minutes, flipping them after 4 minutes. Spray more oil on the other side and cook for an additional 2-3 minutes. Use tongs to handle the skewers safely.

For a smoky flavor, turn on the stove to high and rotate the skewers over the flame, being careful not to let them touch the flame directly.

Once cooked, sprinkle the paneer tikka with chaat masala while still warm. Serve with lemon wedges, sliced onion, and green chutney.