How to cook
Cut the ham into small cubes, crumble the feta cheese, put them all in a bowl.
Add the softened butter. Stir everything.
Smear the bread slices with this, stick the slices together in pairs.
Dip them in the milk, then in the eggs beaten with the flour.
Fry in preheated oil on both sides until reddened.
You can substitute the salty filling with a jam or marmalade but make sure it's thick so it doesn't run.