Heat the olive oil and butter in a large Dutch oven or heavy pot over medium high heat. Saute the onions until tender and translucent, about 5-7 minutes. Add the garlic and cook for another minute. Add the bell peppers and the paprika powder and cook for another 7-8 minutes until tender. Add the tomatoes and chicken and cook for another two minutes. Add the caraway seeds, bay leaves and cracked peppercorns. Stir to combine. Pour in enough of the chicken broth to just cover the mixture, about 4 cups. Bring the goulash to a boil, reduce the heat to low, cover and simmer for one hour. Add salt and pepper to taste.