1tablespoongrated Parmesan cheese(See notes below for additional options)
1/4cupchopped scallions,green parts
1/3cupfirm cherry tomatoes,halved
Olive oil spray
Heat a nonstick 8-inch skillet over medium heat, 2-3 minutes.
Meanwhile, in a medium bowl, vigorously whisk the egg whites with the salt, pepper, and garlic powder, until frothy. Whisk in the parmesan.
Using a spatula, fold the green onions and tomatoes into the egg whites. You can also scatter the vegetables on top of the eggs after you pour them into the skillet, as shown in the video. But I prefer the method of stirring them into the eggs before you pour them into the skillet.
Lightly spray the skillet with olive oil spray, then pour the egg whites in and start cooking them, tilting the skillet to spread them evenly.
As soon as the edges start to set, reduce the heat to medium-low. Gently and repeatedly lift the edges of the omelet, and tilt the skillet to allow the still-runny egg whites to slide to the bottom of the pan, where they will cook faster. The video below shows you how to do that.
When the bottom of the omelet is cooked and the top is not runny anymore but still wet, carefully flip the omelet. I sometimes use two large spatulas for this task. Another method, shown in the video below, is to place a large plate on top of the skillet (careful - it will be hot), invert the omelet into the plate, then slide it back into the pan, cooked side up.
Fold the omelet, slide onto a plate and serve.
Instead of the parmesan, you can use a variety of other cheeses. I sometimes use shredded cheddar, for example, or crumbled feta. If using a cheese other than parmesan, you can use a little more of it - up to 1/4 cup.