Sweet potato soup

Found this recipe on this website:
http://paleodietlifestyle.com/sweet-potato-and-sausage-soup/
I left out the sausage though. I got home quite late and it takes a while making it so my dinner was finished very late but it tasted good at least.

Ingredients
1 3/4 lbs sweet potatoes, peeled and roughly chopped;
1/2 lb of your favorite spicy pork sausage, casing removed;
2 large carrots, roughly chopped;
2 celery stalks, roughly chopped;
2 cloves garlic, minced;
1 1/2 tsp curry powder;
2 onions, roughly chopped
7 cups chicken stock;
Cooking fat;
Sea salt and freshly ground black pepper to taste

Heat a large pan and add some cooking fat and the sweet potatoes, carrots, celery, garlic, onions and curry powder. Combine well.
Cook, stirring occasionally, for about 8 minutes, until the carrots and sweet potatoes are slightly soft.
While the vegetables are cooking, pour the chicken stock in a pot and bring to a boil.
Add the cooked vegetables to the hot stock, bring back to a simmer and simmer for about 10 minutes, until the sweet potato cubes are cooked through.
Season to taste with sea salt and freshly ground black pepper, pour everything in a blender or food processor and process until smooth.