Preheat your oven to 400°F (200°C). Grease a 24-cup mini muffin tin generously with oil or cooking spray, or line two baking sheets with parchment paper.

In a small saucepan, combine the milk, oil, and salt. Heat over medium heat, stirring occasionally, until the mixture just begins to simmer and steam rises — about 3-4 minutes. Do not let it boil.

Place the tapioca starch in a large bowl or the jar of a blender. Pour the hot milk mixture over the starch all at once and stir vigorously (or blend) until combined. The mixture will look clumpy and shaggy at first — this is normal.

Allow the dough to cool for 5 minutes until it is warm but not scalding hot. Add the eggs one at a time, beating well after each addition (or blending between additions) until the dough is smooth and glossy.

Add the grated Parmesan and shredded mozzarella to the dough. Stir or blend until fully incorporated. The dough will be sticky, wet, and pourable — this is correct.

Using a spoon, small cookie scoop, or squeeze bottle, fill each mini muffin cup about three-quarters full. Alternatively, drop tablespoon-sized mounds onto the prepared baking sheets, spacing them 2 inches apart.

Bake for 20-25 minutes, until the rolls are deeply golden and puffed. They should feel set on the outside but still have a very slight jiggle in the center. Do not overbake — you want the inside to stay stretchy and gooey.

Remove from the oven and allow to cool for 3-5 minutes before serving. Serve warm for the best texture and maximum cheese pull.