Wash and pat chicken dry.
In a heavy skillet, heat oil over medium heat; mix in paprika. Brown chicken on all sides; sprinkle with the flour, salt, and pepper. Pour boiling chicken broth or water over the chicken. Arrange potatoes onions around the chicken. Reduce heat to low, cover, and simmer for about 45 minutes, until potatoes are tender and chicken is cooked. Remove vegetables to a platter. Stir into the remaining liquid (skim off fat if desired) the evaporated milk and vinegar. Heat through and serve with the chicken.