Prepare the Spinach:

1. Blanch Spinach: Bring a large pot of water to a boil. Add the spinach leaves and blanch for 2-3 minutes until wilted. Remove the spinach with a slotted spoon and immediately transfer to a bowl of ice water to stop cooking. Drain and squeeze out excess water.
2. Blend Spinach: Blend the blanched spinach in a blender or food processor with 1/2 cup water or chicken broth until smooth. Set aside.

Cook the Sauce:

1. Sauté Aromatics: Heat oil or ghee in a large skillet over medium heat. Add cumin seeds and let them sizzle for a few seconds. Add the chopped onion and cook until golden brown, about 7 minutes. Stir in the minced garlic, ginger, and green chilies. Cook for another 2 minutes.
2. Add Tomatoes and Spices: Add the chopped tomatoes to the skillet. Cook until the tomatoes break down and the mixture thickens, about 10 minutes. Stir in ground coriander, ground cumin, turmeric powder, garam masala, and chili powder. Cook for another 2-3 minutes.
3. Combine Spinach: Stir in the blended spinach puree and simmer for 5-10 minutes. Adjust seasoning with salt and sugar (if using).

Prepare the Paneer:

1. Fry Paneer: Heat oil or ghee in a separate pan over medium heat. Add the paneer cubes and cook until golden brown on all sides, about 5-7 minutes. Remove from heat and set aside.

Combine Paneer and Sauce:

1. Add Paneer to Sauce: Gently fold the fried paneer cubes into the spinach sauce. Simmer for 5 minutes to allow the flavors to meld. Adjust seasoning as needed.

Serve:

1. Accompaniments: Serve hot with basmati rice or naan bread.