Stir together thick yogurt (refer notes), chilli powder, garam masala, turmeric, coriander powder, kasuri methi, chaat masala, ginger garlic paste and salt.
Optional for restaurant flavor - In a small pan, mix 1 tablespoon besan with the oil called for in the recipe (1½ tablespoons). Fry on a low heat until fragrant. Cool this and mix in the marinade along with ajwain.
Pour oil and mix everything well. Check salt and spice. If needed add more salt and chilli.
Add the cubed capsicum and onions. Mix well. Then add paneer cubes and gently coat them with the marinade.
Cover and rest this in the fridge for 1 to 2 hours. Overnight marination may break the paneer.
Begin to thread the chunks of capsicum, onion and paneer alternately on the skewer.
If making in oven, you can use large bamboo skewers. If making on tawa, you can use small ones. You will be able to thread these on 3 large or 4 small skewers.
Preheat the oven at 450 F or 230 C for at least 15 mins.
Prepare a baking tray and line a parchment paper.
Place the skewers on the tray. Spray oil to avoid the paneer and veggies drying out.
Grill them for 10 to 11 mins. Brush them with the leftover marinade. This will prevent them from turning dry.
Move the tray to a higher rack and broil for 2 to 3 mins until slightly charred.
Do adjust the grill timings based on your oven and the size of paneer cubes. Over cooking may char them too much. When they are golden or lightly charred, take them off the oven.
Brush paneer tikka with butter or mustard oil. Serve them with mint chutney, onion and lemon wedges.
Optional: For restaurant flavors, Place a small steel bowl in the serving plate. Burn a wood charcoal piece on direct fire until red hot. Keep it in the bowl. Pour ½ tsp ghee over it. It should begin to smoke immediately. Cover with a foil and let it smoke for 5 to 6 mins.
Heat a tawa with 1 tbsp oil and spread it evenly all over.
When the tawa is hot enough, place the skewers and cook on a medium heat.
Keep checking and turning them around to all sides for even grilling.
When they turn golden, place a wired rack over a direct fire like gas stove. Place these skewers over the fire and grill on direct flame until char grilled. This step will ensure all of the marinade is cooked through on all the sides.
Remove to a plate and brush them with butter. Serve paneer tikka hot as a appetizer or a side in your meal.
Air fry the paneer tikkas at 390 F or 200 C for 5 mins. Later brush them with some marinade and continue to air fry for another 2 mins.
Lastly brush them with butter or mustard oil.