To make this firstly cut the bel or wood apple and remove the pulp with the help of knife in a bowl.

Now add water in it and mash the pulp using or hands, sieve in another bowl to remove it's seeds.

Add sugar and milk in it and blend it by blender or mixer.

Lastly just take it out in a glass and topped it with pistachios.

Tip 1 : Have it immediately because after some time it gets bitter.

Tip 2:Vary quantity of sugar as per your choice.
Never blend bel directly because it's seeds are bitter.