Bring a large pot of salted water to a boil. Prepare a large bowl of ice water and set it nearby. Add the spinach to the boiling water and blanch for 60 to 90 seconds until just wilted and bright green.

Using a slotted spoon or tongs, immediately transfer the spinach to the ice water bath. Let it cool for 2 minutes, then drain well and squeeze out as much water as possible. Set aside.

Pat the paneer cubes dry with paper towels and season with a pinch of salt. Heat 1 tablespoon of ghee in a large skillet or Dutch oven over medium-high heat.

Add the paneer cubes in a single layer without crowding (work in batches if needed). Sear for 2 to 3 minutes per side until golden brown. Transfer to a plate and set aside. Optionally, soak the seared paneer in a bowl of warm water for 5 minutes to keep it extra soft.

In the same skillet, add the remaining 1 tablespoon of ghee over medium heat. Add the cumin seeds, cinnamon stick, and cardamom pods. Let them bloom for 30 to 45 seconds, stirring frequently, until the cumin sizzles and smells toasty.

Add the chopped onion and cook, stirring occasionally, for 8 to 10 minutes until softened and lightly golden.

Add the garlic, ginger, and green chili. Cook for 2 minutes, stirring constantly, until fragrant.

Add the chopped tomatoes along with the ground coriander, turmeric, Kashmiri red chili powder, and half the salt. Cook for 5 to 6 minutes, stirring and breaking down the tomatoes, until they are completely softened and the mixture begins to come together into a thick paste.

Remove the cinnamon stick and cardamom pods if you prefer (or leave them — they will continue flavoring the sauce). Add the blanched spinach to the pan. Stir to combine everything thoroughly.

Using an immersion blender directly in the pan, blend the spinach mixture to your desired consistency — completely smooth for a silky sauce, or partially blended for a more rustic texture. Alternatively, carefully transfer to a countertop blender in batches and blend, then return to the pan.

Place the pan back over medium-low heat. Stir in the garam masala and remaining salt. Taste and adjust seasoning. Let the sauce simmer gently for 3 to 4 minutes.

Add the pan-fried paneer cubes to the spinach sauce. Stir gently to coat and simmer together for 3 to 4 minutes so the paneer absorbs the flavors of the curry.

Stir in the heavy cream or coconut cream. Taste one final time and adjust salt or garam masala as needed.

Serve hot over basmati rice or with warm naan. Garnish with a drizzle of cream, a pinch of garam masala, and fresh ginger matchsticks if desired.