Apples and sweet potatoes are a natural pairing in the world of food. This delicious fruit and vegetable duo can be found in all sorts of healthy dishes. This hearty soup is low in fat, high in nutrients and, thanks to the addition of a little bourbon, a warm welcoming snack on a chilly autumn day. Feel free to use apple cider that is either alcoholic or non-alcoholic.
Preheat the oven to 400 degrees and bake the sweet potatoes for one hour, or until tender. Remove the potatoes and allow them to cool completely and then peel them.
Caramelize the onions as the potatoes bake by melting the butter in a large saucepan over medium-high heat. Add the onions, turn the heat down to medium-low and slowly saute the onions until they are golden brown and very tender. This will take about 20 minutes and you should stir often.
Put the onions, sweet potatoes and apple cider in a food processor and process in batches, pureeing until smooth. Return the puree to the saucepan and turn the heat to medium.
Add the bourbon and the chicken stock and bring everything to a boil. Reduce heat and simmer the soup for about five minutes. Season with salt and pepper.
Serve the soup by pouring it into bowls and garnishing with a sprinkle of chopped walnuts and sage leaves.