Royal Icing for Gingerbread houses

I got this recipe from here: http://easteuropeanfood.about.com/od/crossculturaldesserts/r/royalicing.htm
You need a stand alone mixer to complete this because it needs to mix really fast, and a really long time. Don't bother with a hand held mixer, you will regret it.

Time: Takes 10 minutes or so.

Ingredients:

1 lb powdered sugar (or more as needed, but i didn't need more)
1/2 cup egg whites (aka 3 large egg whites)
1/2 tsp cream of tartar

Directions:

1. Place all ingredients in large mixing bowl and combine. Turn stand alone mixer to high and beat until thick & very white. Mixture will hold a peak. This takes at least 7-10 minutes.
2. You're done! If not using right away, cover with plastic wrap, making sure it touches the icing so a crust doesn't form. (Icing dries quickly, so cover it all the time.)

yes, I'm a homeowner now!