Heat butter (2 tbsp) in a pan. Sautee green chilies (2) and cashews (10). Add onions (2) and fry until golden. Add ginger (1 inch) and garlic (2 cloves) and sautee for 2 minutes. Add cumin powder (1 tsp), garam masala (1 tsp), and turmeric powder (1/2 tsp) and sautee for 1 minute. Add tomatoes (2) and salt (1 tsp). Sautee for 2 minutes. Add 1/2 cup water and cook covered until onions are completely soft.
Add spinach (500g) for 3-4 minutes until leaves wilt and raw spinach smell dissipates. Remove from heat and let cool. In a food processor, blend this to a smooth puree. Add water if you need to.
In the same pan, add butter (1 tbsp). Then add whole spices: cardamoms (3), cinnamon (1 inch), cloves (2), cumin seeds (1/4 tsp), and bay leaf (1). Add cubed paneer (200g) and sautee for 2 minutes.
Lower the heat and add the kasuri methi (1/2 tsp) and pureed spinach mixture. Cook for 2-3 minutes. Don't overcook or else the spinach will lose its vibrant colour.