Wash and scrape the potatoes and boil them in a covered pot until thoroughly cooked. Drain off and reserve the cooking water. When the potatoes are cool, dice them and set them aside. Fry bacon slices until crisp. Put bacon fat into a heavy pot and saute the onion in it until soft. Add the flour and cook until bubbly. Add the potato water to the dried skim milk and enough additional water to make a quart. Stir milk mixture quickly into the flour mixture, cooking until thickened. Flavor with salt, pepper, paprika, chives, and garlic salt. Add the potatoes and cook slowly for 10 minutes. Crumble bacon on top and serve.