This video by PastelBunBun.com provides instruction on how to make fresh Royal Icing using egg-whites instead of meringue powder. Ingredients:
2 Egg Whites
Half TSP Cream of Tartar
How To Make:
Put egg whites into blender and whip until foamy.
Add half a TSP of cream of tartar.
Add powdered sugar.
Whip everything together on the highest speed of your mixer until everything is the right consistency as what you see in the video (makes shaped peeks)