Potato Soup With Butter Dumplings

• 2 tab flour
• 2 eggs (beaten)
• 1 onion (chopped)
• 1 stalk celery (chopped)
• 950 ml water
• 550 gr potato (peeled)
• 230 ml carton sour cream
• 55 gr butter
• 28 gr butter softened
• 8 gr salt