Heat 3 tablespoons oil in a large frying pan or kadhai. Fry the paneer till golden brown. Remove and set aside. Add another tablespoon oil. Add the onions, capsicum, ginger, and garlic and fry till onions are browned, about 5 minutes.
Add the turmeric powder, saunf powder, and garam masala. Fry for 30 seconds till fragrant. Add the tomatoes and tomato sauce, and salt. Cook till tomatoes are cooked and the oil separates from the gravy. Add ½ cup water to thin out the gravy.
Add the paneer and cook on high heat till the gravy is thick, about 10 minutes. Sprinkle coriander leaves and serve.