The ancient Viking kitchen was characterized by its reliance on preserved foods and hearty ingredients. While they did not have a built-in sous-vide cooking station, they used a method called 'hot stone cooking.' This involved heating stones in a fire and then placing them in a pot filled with water or broth. The food would be added to the pot, and the hot stones would slowly cook it, resulting in tender and flavorful dishes. The ancient Vikings also used a variety of herbs and spices, such as dill and juniper, to enhance the taste of their meals.