Curry leaves is an ingredient which is used quite often in the cuisines of South India and Western India. They are hardly used in Bengali or North Indian cuisine. The favoured herb for the latter two is coriander/ cilantro or 'dhaniya' as it is called here.
I made an interesting combination this morning while making an omelet for breakfast. I added some curry leaves which were in the fridge and sauteed it with onions, tomatoes and chopped green chillies before adding the egg white to it. It gave a nice, sharp flavour which was different from that of coriander leaves which are more commonly used in omelets.
Tip: How to separate the egg white. I crack an egg into a bowl. I then use a spoon and literally scoop out the egg yolk into another bowl. I guess this also works if you are following a recipe from Nigella Lawson and want only egg yolks!
I also add a bit of milk to omelets which gives it a nice fluffiness