How to cook
Peel the potatoes, cut them into small cubes, and put them to boil in salted water together with the finely chopped celery leaves and the leek.
When the vegetables are soft, strain and mash the potatoes.
Make a roux with oil and red pepper and dilute it with the resulting puree. Add the crushed feta cheese or grated cheese, savory, and a lump of butter for a better taste.
Add water if necessary to dilute the soup and bring to a boil, adding a glass of milk. Finally, season with salt and pepper.
Make a liaison for the soup with the beaten egg and lemon juice.