In a pan heat ghee and add paneer, mawa, sugar, cardamom powder and chopped pistachios.
Roast for a minute or two and allow it to cool.
On a parchment paper, apply butter in a triangular shape using a spatula.
Allow it to set in fridge for 20 minutes.
Now place the filling in the centre of the triangle and bring the sides of the butter to overlap the filling.
Refrigerate until firm.
Sprinkle caster sugar on the samosa and serve immediately.