Combine flour, paprika and salt; mix well. Dredge pork in flour mixture. Reserve excess flour mixture.
Brown pork in oil in a large skillet or Dutch oven. Pour off drippings. Add 1/2 cup water and onion, cover tightly and cook over low heat for 30 minutes.
Add potatoes and continue cooking, covered, 20 to 30 minutes or until pork and potatoes are tender.
Combine reserved flour with 2 tablespoons water; stir into pork mixture and cook until thickened, stirring occasionally.
Remove from heat and stir in sour cream.