This recipe uses pasteurized egg whites as a whole food protein source. Even though they are not being cooked, they are pasteurized which mean you don't have to worry about contracting Salmonella from eating raw eggs (although I would still avoid raw pasteurized egg whites if you are pregnant). Eggs are a great source of protein, and I prefer to eat whole foods instead of adding in protein powders, although powders can be a great option if you can't tolerate eggs.
You can add in any vegetables you have in your fridge to make this a nutritious smoothie, here is an example of what I just had for breakfast.
2 large handfuls of greens (I used a mix of kale, spinach and arugula)
1/2 raw beet (peeled)
2tbsp of parsley
Juice of 1/2 lemon
6 inches of cucumber, sliced into 2 inch chunks
1 small carrot
Thumb-sized amount of ginger
Handful of blueberries
Enough water to help blend, about 1 cup
A few ice cubes
1/2 cup pasteurized egg whites
Optional: 1tsp honey for added sweetness
Combine all ingredients, except egg whites, into blender (I can't recommend the VitaMix enough - it is worth the investment and will blend all of these ingredients in seconds). Once your smoothie is blended, add in the egg whites and blend for 15-20 more seconds.