To make a little froth, combine the egg whites with the black pepper and salt in a bowl and whisk to combine.

Preheat a nonstick pan and add the olive oil. Sauté the red pepper and onion for 1 minute. Cook the tomato and spinach for one more minute, or until the spinach has just wilted.

Pour the whisked egg whites over the veggies. Make sure to distribute them evenly. Cook on low heat until set. If you're using cheese, sprinkle some on top at the end.

After the omelette has cooked, carefully fold it into a wrap. Cut in half and enjoy while still warm.