1. In a bowl, add egg white, leek, carrot, curry or turmeric powder, salt and cheese and mix well.
2. Heat 1 tsp mayonnaise in a rectangular pan over medium heat, pour a little bit of egg mixture to see if the pan is hot.
3. Pour egg mixture in the pan, tilting to cover the bottom of the pan. Start to roll into a log shape from one side to the other.
4. Move the rolled omelette to the side where you started to roll, and pour the egg mixture to cover the bottom of the pan again. Repeat rolling from one side to the other until all egg mixture finish.
5. Slice the omelette in about 2cm cuts and serve!