Steps:
1. Sieve tapioca flour and put it in a large bowl. Preheat the oven to 180°C.
2. Mix milk, oil, salt evenly, and bring them into a soft boil. Mix tapioca flour with the puree and mix until no more dry tapioca flour could be seen.
3. Add grated Parmesan cheese into the dough. Add the egg into the dough, half at a time.
4. Put oil on hand and shape the dough into even balls.
5. Baked them in the preheated oven for 25 minutes.