Preheat the Oven and Prepare the Pan:
Preheat your oven to 375°F (190°C). Grease a mini muffin tin or line it with mini muffin liners.

Heat the Liquid Ingredients:
In a small saucepan over medium heat, combine the milk, butter, and salt. Heat until the butter is melted and the mixture is hot but not boiling.

Mix the Tapioca Flour:
Place the tapioca flour in a large mixing bowl. Pour the hot milk mixture over the tapioca flour and stir until well combined. It will be grainy and gelatinous at this stage.

Add Cheese and Eggs:
Let the mixture cool for a few minutes so it won't cook the eggs upon contact. Add the cheese and eggs, mixing well until smooth. The batter will be sticky and stretchy.

Bake the Pão de Queijo:
Spoon the batter into the prepared mini muffin tin, filling each cup about three-quarters full.
Bake in the preheated oven for 15-20 minutes, or until they are puffed and lightly golden.

Serve:
Remove the pão de queijo from the oven and let them cool slightly before removing from the pan. They are best served warm.