Keep ice-chilled water within reach.
In a bowl, mix plain flour and corn flour together.
Add garlic powder, black pepper powder, salt, baking powder, and fruit salt to the mixture, then whisk it.
Now, add one egg to the mixture.
Gradually add chilled water, starting with 1 cup, until the batter reaches the desired consistency.
As needed, adjust the amount of water.
The batter should be slightly thick.
Let the batter sit at room temperature for 15 minutes.
Melt butter and add it to the batter, then mix it well.
Allow the batter to rest for an additional 15 minutes before using it to make the fries.
Give the batter a final whisk before using.