Boil 4 to 5 cups of water. Put whole lemons into the boiling water and allow to boil for five to ten more minutes. Remove the lemon and cool it.
Cut the lemon into desired size pieces and spread it on a plate. Sprinkle chilli powder, asafotida powder, fenugreek powder and salt. Heat oil in a kadai and when it is hot add mustard. After it pops up, remove and pour the hot oil over the lemon pieces. Mix everything well and transfer it to a bowl.