Add sour cream and two eggs to a frying pan with a little oil. Mix everything together and cook the egg mixture over low heat. To maintain a creamy consistency, gather the egg mixture to the edge of the pan and remove from the heat.
Brush one side of the tortilla with butter, then flip it over and top with cheese, egg mixture, ham and more cheese.
Fry in a dry frying pan over medium heat until golden brown.
Serve immediately, before the cheese melts. For a more delicate flavor, add cold sour cream.
