Heat the butter and oil over medium-high heat in a large saucepan or soup pot. Add the beef and onions, and cook stirring occasionally, until the onions are golden.
Lower the heat to medium-low. Add the caraway, thyme, and garlic. Sprinkle in the paprika and flour, and cook stirring until they are well blended. Stir in the vinegar.
Gradually stir in 2 cups of the broth. Pour in the remaining broth, bring to a boil, lower the heat and simmer uncovered for 45 minutes or until the beef is almost tender. Add the potatoes and cook 30 minutes, or until the beef and potatoes are tender. Taste for seasoning before adding salt. Sptinkle with chopped chives and serve.