Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside.
In a large bowl, use a wooden spoon to evenly combine starch, coconut flour, and salt. Slowly pour in water and oil, mixing until blended.
Add the egg and stir until combined. If the mixture is too wet, add more coconut flour as needed, 1 Tbsp at a time, waiting slightly between additions (this will give the coconut flour time to absorb the liquid and you can have a better gauge whether ore is needed or not).
Using a small cookie scoop, place balls of dough on the baking sheet an inch or so apart (these rolls do not spread).
Bake for 30-35 minutes, or until slightly browned on the bottom. Remove from baking sheet and serve warm.
Best eaten the same day.