Peel and finely chop the onion. Trim and chop the carrot and celery to match. Warm a large pan on a medium heat and add 1 tbsp olive oil. Add the veg and fry for 5 mins till softened.
While the veg cook, peel and finely grate or crush the garlic. Roughly chop the tomatoes.
When the veg have cooked for 5 mins, add the garlic and tomatoes. Tip in 2 tsp chilli spice blend with a pinch of salt and pepper and stir. Cook for 5 mins till the tomatoes have softened.
Meanwhile, drain and rinse the aduki and borlotti beans. Fill and boil the kettle.
When the veg have softened, add the beans. Pour in 700ml hot water from the kettle and crumble in the stock cube. Bring the soup to a bubble, pop on a lid and simmer for 15 mins.
Finely chop the coriander stalks and roughly chop the leaves, keeping them separate.
When the soup has cooked for 15 mins, add 1 tsp raw cacao nibs and the coriander stalks. Taste the soup and add more salt or pepper if needed. Ladle the soup into 2 warm bowls. Stir 1 tbsp soured cream through each, and top with the coriander leaves to serve.