Heat 1/2 tsp oil in a wok and add peppercorns and let it splutter.
Add other spices and roast it for two minutes
Add 1 1/2 onions( chopped),curry leaves, ginger garlic paste and coconut and saute well. Switch off the flame and let it cool .Blend well in a mixture and keep it aside.
Heat the remaining oil in a wok and add half chopped onions and saute well for a minute.
Add chopped tomatoes and saute till it is mushy. Add blended mixture and turmeric powder and salt to taste and mix well with 3 cups of water and cook for 15 minutes.
When the raw smell disappears the oil starts to float at top. Add paneer cubes and cook for another 5 minutes.
Chettinad paneer is ready. Garnish it with coriander leaves