Begin by prepping vegetables and setting aside for assembly. If bread needs slicing, do this as well.
Heat a medium skillet, then whisk together 1 whole egg and 2 egg whites. Coat pan with cooking spray, and cook eggs until no longer runny, flipping over at least once.
Toast 2 slices of bread, and spread 1/8 cup avocado on one slice of bread. Top the second piece of bread with slice of cheese, cooked eggs, 1-2 slices of tomato and close sandwich. Repeat for each egg-wich.