Preheat the oven to 350°F (180°C). Line a baking sheet with parchment paper or a silicone mat and set aside.
Sift all-purpose flour, chickpea flour, semolina, and salt together, whisk well, and set aside.
In a mixing bowl, take Ghee and icing sugar and whisk well until the mixture is light, fluffy, and pale in color.
Add cardamom powder and vanilla and whisk until well combined.
Add dry ingredients to the wet mixture and mix gently, initially with a spatula and then with your hands, until a very soft and smooth dough is formed.
Do not overmix or knead the dough. The dough should be soft but not sticky.
Spoon the dough and make an equal size of balls. I used a very small ice cream scoop to make approximately 1 & ½ tablespoon of dough balls. I could make 18 balls.
Flatten each ball slightly and place them on a baking sheet. Keep a good distance between each ball, as the Nan Khatai will spread during baking.
Make an indent in the center of each ball with your finger or thumb, and place chopped pistachio on it.
Bake the NanKhatai for 14-16 minutes or until the bottom is lightly golden. Keep an eye on Nan Khatai after 10 minutes of baking, as each oven is different.
Remove NanKhatai biscuits from the oven, let them cool on the baking tray for 5 minutes, and then transfer them to the cooling rack.
Let NanKhatai cool completely, and then store in an airtight container.