Preheat the oven to 375°. Add the tapioca flour to a large bowl and set aside.
Add the butter, milk, and salt to a medium saucepan and heat over high heat. Bring to a boil and remove from the heat. Pour the hot liquid over the tapioca flour and mix until smooth. Set aside to rest for 10-15 minutes.
After the dough has rested, add the parmesan, cheddar, and eggs. Mix until combined. It will be a pretty soft dough.
Drop 1-1/2 tablespoon sized scoops onto a baking sheet or into a greased muffin tin. If you want to roll them into balls, grease your hands with oil and gently roll before placing them on the baking sheet.
Bake for 10-12 minutes, until the tops are lightly browned. Serve warm.