Cut the paneer into 5-cm / 2-inch square pieces, about 2.5cm / 1-inch thick and set aside.
Put the spinach, chillies, ginger, salt, and a sprinkling of water in a large, heavy-based pan and cook over medium heat for about 3-4 minutes, or until cooked.
Allow to cool, squeeze dry, then transfer to a blender or food processor and process to make a puree. Set aside.
Heat the oil in a heavy-based pan over medium heat, add the fenugreek seeds, and stir-fry for about 30 seconds. Add the onion and stir-fry for about 5 minutes, or until it is lightly colored. Add the garlic and cumin seeds and fry for 30 seconds, then add the pureed tomatoes and fry for a further 5 minutes, or until the liquid from the tomatoes has evaporated.
Add the paneer and stir gently, then add the pureed spinach and cook for 2 minutes before serving.