Take milk in a pot, and heat it to a boil. As it starts boiling, lower the heat and add the lemon juice.
Keep adding lemon juice until the milk is curdled fully and starts separating into whey curds.
Run the milk-whey mixture through a sieve and collect the chena. Let the chena rest for 15-20 minutes.
Press the rested chena gently to drain it off water, but not too much that it loses all of the moisture. Add cornflour and start mixing it with your hand. Mash the chena using your hands for 10 minutes.
Make small flat balls out of the mashed chena and keep them for aside to be boiled in the sugar syrup.
In a heavy bottomed pan, take sugar and water and bring it to a boil. Once the mixture starts boiling, drop the chena balls in it. Let it boil in the syrup for 15 minutes. Heat should be kept high throughout the process.
Take the balls out and let them cool completely. We shall prepare the malai/thickened milk next to put these balls in.