SWEET POTATO SOUP WITH GINGER, LEEK AND APPLE

Steps:

• Heat the oil or butter in a heavy soup pot or Dutch oven over medium heat. Add the leek and cook, stirring, until it is tender, about 5 minutes. Add the ginger and stir together until fragrant, about 1 minute. Add the sweet potatoes, regular potato, apples and water and bring to a simmer. Add salt to taste, reduce the heat, cover and simmer 45 minutes to an hour, until all of the ingredients are thoroughly tender.
• Using an immersion blender, purée the soup (or you can use a regular blender, working in batches and placing a kitchen towel over the top to avoid splashing) until very smooth. Return to the pot, heat through and adjust salt. Ladle into bowls, squeeze a little lime juice and sprinkle a little chili powder over each serving and serve.