I was inspired by the spinach, egg-white and melted cheese breakfast muffin I had in New York.
Very simple to make:
Sauté three handfuls spinach in olive oil. Add 2 egg-whites and cover pan. Leave for 2-3 mins to cook. Meanwhile, toast your bread/muffin. Add salt and pepper to pan and crumble on some feta cheese. Stir it up a bit, letting the cheese melt slightly. Spoon mixture into sandwich, et voila! I reckon it might be quite nice in warm wholemeal pitta bread as well.