Using medium heat, sauté onion and paprika in oil, stirring together for a few minutes. DO NOT LET ONION PIECES GET BROWN. Add chicken. Cover pan. Simmer slowly for 5-7 minutes on EACH side.
Add chicken broth, salt and sugar. Cook covered, low heat, 1-1/2 hours. About 5 minutes before chicken is done ... in small dish blend flour (or cornstarch), sour cream, and a little chicken broth together.** Remove chicken from pan and place on separate dish.
Slowly stir in flour/sour cream mixture into sauce stirring CONTINUALLY until sauce becomes a little thick. Return chicken to sauce and simmer together for about 5 minutes. Serve with spaetzles, egg noodles, rice or pasta!! (You usually have enough gravy to pour on noodles)!