Put a frying pan on the stove to heat.
Combine the egg with milk and a pinch of salt, beat with a fork until smooth.
Put cheese and ham on one slice of bread, cover with another slice of bread. Cut the resulting sandwich in half to make two triangles.
Pour vegetable oil into a skillet. Quickly, so as not to soften the bread in milk, dip the prepared croutons in a mixture of eggs and milk, then roll in breadcrumbs.
Fry the croutons with a secret on both sides in heated oil.