In a large Dutch oven (or heavy-bottomed pot) over medium heat, add the olive oil. Add the andouille sausage and sauté until lightly browned.
1 tablespoons olive oil, 12 ounces andouille sausage
Add the chicken stock, scraping up the browned bits.
5 cups chicken stock
Take the 1 cup reserved black beans and in a bowl mash them with the back of a fork. If need be, you can add a little of the chicken stock to this to make it easier to mash.
45 ounces canned black beans
Add all of the beans to the chicken stock. Then add in the chopped potatoes, spices, salt, and pepper.
2 large sweet potatoes, 2 tablespoons cumin, 2 teaspoons coriander, 1 teaspoon kosher salt, 1/4 teaspoon black pepper
Bring the soup to a boil and then reduce it to a simmer. You should still be able to see grape-sized bubbles. Simmer for 15 minutes or until the potatoes are soft. Taste the soup and add more salt or pepper as desired. Serve and enjoy.