Heat 2 tablespoon oil in a heavy-bottomed pan.
Add chopped ginger and garlic and fry till garlic looks tender. Now add sliced onion. When onion turns translucent put the diced tomato. Cook till the tomatoes wilt completely.
Let the mixture cool. Put it in a blender and make paste. You may a couple of spoons of water if it does not grind well.
Heat ghee in a pan, when its hot, add cashew pieces, fry them till golden. Sprinkle kasoori methi, stir. Add salt, red chili powder and immediately pour the onion mixture paste into the pan. Put 1/4 cup water. in the pan, stir well and let it come to a boil.
Slowly incorporate the milk, stirring frequently. Toss in the paneer cubes and simmer for a few minutes.
Serve hot.