Thinly sliced the onion, cabbage and carrot. Add in a bowl and mix with eggs, season with salt and pepper. Add oil in hot pan, add the egg mixture, cook under medium heat until both sides cooked. 

Spread some butter on both sides of the bread, put in hot pan and cook until both sides golden. 

Sprinkle some sugar on toast, then place the omelette on top. Put a slice of ham and cheese, add in ketchup and mayonnaise, place one more toast on top. Enjoy!