Mix the flour, chilli, salt, pepper and mineral water in a plate.
Add the eggs and whisk well
Heat the olive oil in a pan. Put the raw grated potato and the thinly sliced white part of the spring onions in the hot oil and fry for a few minutes on the highest setting. Turn it around.
Then add the egg mixture and lift and rotate the pan so that the egg mixture covers the entire pan. Turn the stove down to half power. It takes a few minutes for the mass to set.
In the meantime, cut the green parts of the spring onion into small pieces and pour over the omelette, as well as the cheese.
Fold one half of the omelette over the other, let it cook for a few more minutes and then serve.