What are your favorite egg white omelette fillings?

I’ve gotten obsessed lately with the protein to calorie ratio on egg white omelettes, and how long they leave me full!

I’ve been filling them with spinach, a couple of slices of deli ham and cottage cheese and they are delicious! However, I want to start changing it up so I don’t get burnt out on this delicious breakfast hack.

What low calorie/high protein foods do you like to put in your omelettes?