Bring a large pot of water to boil. Add spinach and blanch for 2 minutes until wilted. Immediately transfer to a bowl of ice water to preserve the bright green colour.

Drain the spinach thoroughly and blend with tomatoes and 2 tablespoons water until you have a smooth puree. Set aside.

Heat 1 tablespoon oil in a non-stick pan over medium heat. Lightly fry paneer cubes until golden on all sides, about 2 minutes per side. Remove and set aside on a paper towel.

In a large pan or kadai, heat remaining oil and butter over medium heat. Add cumin seeds and let them splutter for 30 seconds.

Add chopped onion and sauté for 5-6 minutes until soft and golden brown.

Add minced garlic, grated ginger, and green chillies. Cook for 2 minutes until fragrant, stirring continuously.

Add turmeric, ground coriander, red chilli powder, and half the garam masala. Stir for 1 minute to toast the spices.

Pour in the spinach-tomato puree and stir well. Cook for 8-10 minutes on medium-low heat, stirring occasionally, until the sauce thickens slightly.

Stir in the double cream, salt, and sugar. Mix until well combined and simmer for 3 minutes.

Gently add the fried paneer cubes to the sauce. Stir carefully to coat and simmer for 5 minutes to allow flavours to meld.

Sprinkle remaining garam masala on top. Taste and adjust seasoning if needed.

Serve hot with steamed basmati rice or warm naan bread, garnished with a drizzle of cream if desired.