Clean the green onions, wash and cut them very finely. Do the same for the spinach leaves. Heat butter in a pan, put the green onions and spinach to saute.
Add 1-2 tbsp water. Season with black pepper and paprika.
Chop the parsley finely, the spearmint as desired, add them to the green onions and spinach. Saute for a few min. to soften well.
Once ready, remove from the stove and stir several times until they cool.
In a bowl, beat 1 fresh egg, mix it with the crumbled feta cheese and finely grated cheese. Add this to the vegetables (green onions, spinach, spices) and stir well.
Arrange slices of bread in a tray and smear them on top with the resulting mixture.
Put the sandwiches in a highly preheated oven with the upper element on to bake until slightly golden.