You need to make the stuffing while you are soaking the pointed gourds.
I make khowa at home. Do check the video/ link, if you wish to make it at home!
Take Khowa or Mawa and grate it.
Transfer the khowa to a non-stick pan.
Keep the flame slow and melt it. Stir continuously.
While cooking, add 1 cup of the syrup (used while cooking the pointed gourd).
Instead of this syrup, you can use milk as well and mix it properly.
Now add 2Tbsp. Sugar and mix.
Now add 1Tsp. ground green cardamom.
Add a few Saffron and mix and switch the flame off.
The mixture should be moderately thick.
Cool it so that it would be easier to stuff the potol for the final step of making potol mishti.