Combine refined flour, 4 tbsps castor sugar and ghee in a bowl. Mix well and rub till it resembles a breadcrumb texture.
Add sufficient water and knead into a semi-stiff dough. Refrigerate for 10 minutes.
Combine chocolate and pistachio in a bowl. Mix well and add 1 tsp castor sugar and mix well.
Divide dough into 8 equal portions and roll out into medium size rotis. Cut the rotis into halves.
Apply water on one edge half and roll into a small cone. Reserve some chocolate mixture for garnishing and place a spoonful of the chocolate mixture from the remaining into the cone and seal to make a samosa. Similar prepare the remaining.
Prepare a thick sugar syrup by cooking sugar in 1 cup water.
Heat sufficient oil in a kadai. Deep-fry samosas on low heat till golden and crisp. Drain on absorbent paper.
Dip samosas in sugar syrup and soak them well.
Garnish with reserved chocolate mixture and serve immediately.