In a thick bottomed pot, bring the milk to boil. When it comes to a roll boil, add the lime/lemon juice, gradually. Switch the flame off and keep stirring. You will see the whey separate
Strain this over a cheesecloth and wash it with fresh, cold water. This is the chaena or Indian cottage cheese. Tie and hang this cloth with the chaena for the excess water to drain off, for 30 minutes
Once done, remove the chaena on a flat surface, break the lumps and knead using your palm to form a smooth dough. Make lime sized balls out of this dough and keep covered, until required
Set the same or another wide pot with the gur, sugar and water to boil. When this syrup starts to bubble, on high flame, drop the chaena balls in. Let it cook for 15 minutes. Do not stir
Lower the flame to medium-low and cook, covered, for another 30 minutes
Once done, turn the flame off and let the rasgullas sit in this sugar-jaggery syrup for 3-4 hours. Thereafter remove and store
Serve your delicious nolen gurer rosogulla (rasgulla) chilled or at room temperature. Enjoy!