In a deep pan add enough oil to cover the bottom of the pan. Heat the oil and sauté the onions until transparent. If using red pepper, add to the pan and sauté until soft. Add the chicken breasts and cook to seal in the juices until the chicken has some colour. Season the chicken with the paprika, salt and pepper. Cover the pan and cook on medium heat for approximately 30 minutes or until the chicken is tender. If using boneless chicken, reduce the cooking time.
Once the chicken is cooked, remove the chicken from the pan. Combine the water and sour cream and set aside. To the juices in the pan, add the flour stirring well to form a roux. Whisk in the sour cream mixture until well blended (a hand blender may also be used to puree the mixture). Place the chicken back in the pan and coat with the sauce. Serve with noodles or rice.
*Note: Adjust the thickness of the sauce by either adding more flour or more water. An easy way to measure the sour cream is to fill a 2 cup measuring cup with the water first, then add the sour cream till you hit the 2 cup mark.
When reheating the dish, do not let the sauce boil.