Buy fresh, good quality parwal from the market. Wash and peel them. Now cut the parwal from the center leaving the bottom part. Do not make a deep cut, the bottom side should be joined so that it can be stuffed.
Take out the seeds from the parwal carefully, so that the shape is not affected.
Take a vessel and heat some water in it. Once the water starts to boil put the parwal into it . Let the water boil again and then boil the parwal for 2-3 minutes. Turn off the flame and cover the vessel with a lid. Leave it for half an hour. Now strain the water from the parwal and put them on a strainer or on a plate. Tilt the plate so that the entire water drips down.
Take another vessel and put sugar and water (1 cup-200 gms) in it. Let the mixture boil to make a syrup (chashni). Make a one string syrup, which is not very thick and do no settles down instantly. Put all the parwal into this syrup and boil until their colour changes. You will experience a beautiful change in the colour. Flip the side of the parwal while boiling it. Turn off the flame, cover the vessel and leave it for 1 hour in the syrup. Let them get sweet. Meanwhile we will prepare the filler to stuff the parwal.
Put khoya in a pan and roast it on a medium flame till it turns light pink in colour. Let it cool down. Grind 30 almonds in the grinder and cut 15 almonds and pistachios in long pieces. Add ground almonds, cardamom and sugar into the roasted khoya. The filler to stuff the parwal is ready.
Take out the parwal from the syrup and put them on a plate. Tilt the plate so that any excess syrup drip off from the parwal.
Now stuff each parwal with the filler and put chopped almonds and pistachios over the filler. Press the filler with light hands so it settles down inside the parwal. Prepare all the sweet in the same manner.
Your Parwal sweet is ready. You ca consume this sweet for over a week when stored in the refrigerator.