Preheat oven to 350° and line two baking sheets with parchment paper
Peel and finely chop the potatoes and the half onion.
Sautee the onion in a pan with the oil until the onions are slightly translucent.
Add the potatoes, salt, and chili powder and cook until the potatoes are soft.
Stir in cilantro and put aside to cool completely.
Work with the pastry dough one tube at a time. Unroll the pastry dough and roll out with a rolling pin until it is about a 10 inch square.
Spread half of the potato stuffing onto each of the rolls. Spread the filling all the way to the side edges but leave some space at the top and bottom to make rolling easier.
Roll the dough tightly, as you would cinnamon rolls and put the log in the refrigerator for a few minutes while you prepare the other rolls.
Remove the chilled log and cut it into about 15 or 16 pieces. (note, the rolls will have lines in them indicating 8 slices, you should double up on those so that you get thinner pinwheels) (refer to photos above).
Bake for 15 minutes