Onion Filling

To prepare the filling, peel and finely dice the onion and sprinkle on the salt. Heat the oil in a small skillet, add the salted onion, and sauté for about a minute. Sprinkle the flour over the diced onions and sauté until they attain a medium/ soft consistency and are coated with a milky paste. Remove from the heat and set aside to cool a bit.