Take greek yogurt, mustard oil, besan, ginger and garlic, all the spice powders and salt. Mix everything well.
Add paneer, onion and pepper cubes. Mix well so the marinade is coated to every piece. Cover it with plastic wrap and let it rest for 1 hour to 4 hours or even overnight (if prepping ahead of time).
Grilling The Tikka (Oven):
Preheat the oven to 450°F (or 230°C) for at least 10 minutes.
Prepare the baking tray with a rack on top. You can line the bottom tray with parchment paper or aluminum foil.
If using wooden skewers, please soak in the water for 30 minutes.
Arrange the paneer and veggies on the skewer and place the skewers on the prepared rack.
Spray generously with the cooking oil spray. Turn the skewers and spray again, so all the sides are coated with the oil.
Roast in the oven (in the middle rack) for 10 minutes. Then turn the broiler on, transfer the tray on top rack and grill for 3-4 minutes or until it gets charred flavor. During the broiling process, halfway through remove the tray, flip the skewers and broil. So it gets charred from all sides.
OR Pan-frying (On Stovetop):
Heat the nonstick pan on medium heat and add a generous amount of oil. Oil should coat the bottom of the pan. Once hot add marinated cubes in a single layer. You may need to do it in batches.
When paneer gets light golden color flip them and cook another side. Cook the veggies till they are 80% cooked. Remove them to a plate and keep it aside.
Making Paneer Tikka Masala Gravy:
Heat the butter in a pan on medium heat. Once hot add whole spices (cloves, cardamoms and cinnamon stick). Saute for 30-40 seconds or until you feel a nice aroma of the spices.
Then add ginger and garlic. Saute for a minute.
Add chopped onion and sprinkle a little salt to speed up the process. Cook until onion becomes soft and translucent (or light pink).
Add cashews and chopped tomatoes. Mix and cook till tomatoes are soft.
Let the mixture cool down slightly and grind into a smooth paste.
Heat the oil in the same pan on medium heat. Once hot add prepared paste. Mix and cook until it becomes thick and most of the moisture evaporated. So stir in between and scrape the sides and bottom of the pan. If it splutters a lot then you can cover it partially.
Now add salt, red chili powder, coriander powder, cumin powder and turmeric powder. Mix well and cook for a minute.
Now add water and simmer for 5-6 minutes.
Add garam masala and kasoori methi. Crush the kasoori methi between your palm before adding to release the flavor. Mix well.
Add grilled tikka and cream. Mix and simmer for 1-2 minutes and paneer tikka masala is ready to serve.
Avoid overcooking tikka: If you overcook the paneer then it becomes chewy and rubbery. Plus, overcooked veggies will taste too soft and mushy.
Extra marinade: If you have any leftover marinade from tikka, then add that into the gravy and simmer for a couple of minutes.
Fix the sour gravy: if by chance your gravy tastes tangy and sour then you can little sugar or some honey.
Gravy consistency: It has to be medium thick (not too watery or not to thick). So adjust the water quantity accordingly. If it’s watery then let it simmer until thickens.
The color of the dish: Restaurant people add food color to get bright orangy (or sometimes red) gravy. I try to avoid the food color in my cooking.