Heat the ghee or oil until hot then fry the paneer until golden brown.
Drain well then cut it into 12mm/1/2 inch squares and set aside.
Heat 2 tablespoons of ghee or oil in a saucepan, add the onions and fry for 8-10 minutes until light brown, stirring constantly.
Add the garlic and ginger and fry for 3 minutes, adding little water if the mixture sticks to the bottom of the pan.
Add the chili powder, salt, cumin, coriander and turmeric powder and fry for 3-4 minutes, stirring from time to time and adding a little more water to prevent it drying out and sticking.
Add the sour cream and spinach, mix well, cover and cook over medium heat until most of the liquid has evaporated, about 15 minutes.
Add the cheese, cover and cook for a further 5 minutes.
Serve hot with boiled rice or a flatbread such as roti, paratha or naan.