Add the garlic, ginger, and green chili; cook until fragrant and the raw aroma fades, 1–2 minutes.
Stir in the tomato and cook until softened and the mixture looks glossy and reduced, 5–7 minutes.
Sprinkle in the coriander powder, turmeric powder, and Kashmiri chili powder; stir and cook 30 seconds.
Add the spinach and toss until completely wilted and tender, 2–4 minutes.
Take the pan off the heat for a minute, then blend the contents to a coarse-smooth puree directly in the pan with an immersion blender (or cool slightly, blend in a countertop blender, and return to the pan).
Return to medium heat; stir in the water, salt, and kasuri methi; simmer gently, stirring occasionally, until the sauce thickens slightly and glossy streaks of ghee appear on top, 5–7 minutes.
Add the paneer, cut into 1-inch cubes; simmer on low just until heated through and soft, 2–3 minutes.
Turn off the heat; stir in the garam masala and heavy cream, cover and rest 2 minutes, then serve hot with roti, naan, or rice.