Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius). Line a baking pan with parchment paper and set it aside.
In a large saucepan placed over medium-high heat, boil the milk, oil, and salt, whisking occasionally. Remove from heat when you see large bubbles forming.
Working quickly, stir in the tapioca flour. The dough will become very tacky and gummy, almost gelatinous.
Transfer the dough to the bowl of a stand mixer fitted with a paddle attachment. Turn the mixing speed to low and gradually increase to medium. Beat the mixture for 2-3 minutes until it becomes smooth.
Add the grated cheeses and mix until incorporated. Turn the mixing speed to low, and add the eggs one at a time. Beat on medium for 2-3 minutes until a sticky, stretchy dough forms.
Using an ice cream scoop, create portions by dipping the scoop in water, scooping the batter, and placing it onto the prepared baking sheet.
Place in the oven and bake for 25-30 minutes, or until the tops and sides are golden brown and the outsides are crisp.
Remove from the oven and allow to cool on the sheet for a few minutes before serving.
