Shred cabbage, carrot, and onion.
Mix eggs with salt, pepper, and the chopped vegetables.
Heat butter in a pan and toast one side of a slice of bread.
Pour the vegetable-egg mixture into the pan and cook it like an omelette.
Place the cooked egg mixture on top of the toasted bread.
Sprinkle sugar and ketchup, then cover with another slice of bread.
Toast both sides until golden brown.