Heat oil in a heavy bottomed kadai, add whole spices, sauté on medium-low heat until aromatic.
Add ginger garlic paste, sauté over medium heat until fragrant.
Add tomato purée, mix well and cook on medium heat until oil oozes from the sides.
Add slit green chillies, red chilli powder, turmeric powder, coriander powder & shahi paneer masala. Sauté on medium heat for another 1-2 minutes.
Lower the heat, add yogurt and cashew nut paste, salt and sugar, mix well and sauté for 2-3 mins on medium heat.
Add browned onion paste, sauté another 30 seconds.
Add 1/4 cup cream, cardamom powder, and kewra water. Mix well. For a silky smooth texture strain the gravy.
Transfer the gravy to a serving platter, place the paneer cubes over the gravy. Garnish with remaining 1 tsp cream. Serve hot along with some flatbread.