In a large bowl, whisk the eggs with milk and then slowly add the sifted flour and salt. Mix until you have a smooth batter, then set aside.

Peel and cut the onions in half lenghtwise, then thinly slice them.

In a large pan, add the bacon cubes and turn on the heat. When they start to sweat, add the onions and sauté until they start to brown.

Remove half of the filling from the pan, then pour half of the batter in the pan.

Cover the pan and let it cook at medium-low heat for a few minutes, checking the bottom once in a while to make sure it doesn't burn.

When the botton is browned, flip the pancake using a large spatula. Add the grated cheese on top and cook for a few minutes more until the other side is brown too.