Mix yogurt, poppy seed paste, mustard paste, and grated coconut in a bowl until well combined.
Next, add turmeric powder, salt to taste, sugar, and mustard oil and combine thoroughly.
Place the paneer pieces in a stainless tiffin box, then top with the prepared mixture. Add the green chilies on top.
Next close the lid of the tiffin box.
Fill a vessel with water and place the closed tiffin box in it. Cover the vessel with a lid.
Allow to boil the water in the vessel for 15-18 minutes, this will help to cook the paneer inside the steel tiffin box.
After that allow the box to cool and then carefully open the lid. Serve this hot paneer bhapa or steamed paneer with white rice.