Heat a non-stick skillet with oil or cooking spray over medium heat. Once hot, add egg whites seasoned with salt and pepper. Cook both sides until set, then remove from the skillet.
Add fresh or thawed frozen spinach to the skillet, cover, and cook for 1-2 minutes until wilted.
Lay the tortilla flat and place the cooked egg whites, wilted spinach, sun-dried tomatoes, and crumbled feta in the center. Wrap it up tightly.
Return the wrap to the skillet to brown on all sides, or use a panini press to crisp it up.