Grate potatoes in a food processor.
Cover with water and stir in salt and
Cover and leave at room temperature
about 7 hours.
Meanwhile, mix grated onions with eggs
and flour and season to taste.
Rinse the potatoes in a colander; squeeze
dry with a tea towel and stir into batter.
Use a ╝-cup measure to scoop for
SautÚ on both sides in a mixture of
butter and olive oil.