Drain and rinse the beans and set aside. Heat oil in large cast iron enamel pot or saucepan. Add the onion, carrots and potatoes; saute until softened. Add the green chile, cornmeal (mix cornmeal with a little water into a paste first) and spice blend. Stir well. Add the beans and stock. Bring to a boil, reduce to simmer until potatoes and carrots are tender. Add salt to taste. If desired, remove half the soup and puree in a blender in small batches. Be careful if soup is hot and only fill blender halfway. Cover top of blender with a towel and start on low power. Return blended soup to remaining soup in pot.
Serve with any of the following toppings: sour cream, Mexican crema, yogurt, sliced avocado, chopped cilantro, grated cheese, sliced scallions, tortilla chips. If desired, add 8-10 ounces diced chicken sausage.