Sweet potato and black bean soup

This is one of the nicest things I've made in ages - and I made it up all by myself! If you think the picture looks odd, it's because I used purple sweet potatoes! They taste just like the orange ones :-)

To cook:
Fry chopped onion, red pepper, garlic and chillis.
Add cubed sweet potato (about 400g), tin of chopped tomatoes, a tin or carton of black beans and enough stock to cover. Cook until potato is cooked.
Add plenty of chopped parsley, lime juice and hot sauce.