Chop the onion and add it to a large pan along with the butter. Sauté the onion for about 5 minutes, until soft and translucent.

Then, add the Thai curry paste and continue to sauté for about a minute more.

While the onion is sautéing, peel and chop the sweet potato into approximately 1 inch cubes. Add the sweet potato to the pot after the curry paste has sautéed, and continue to cook the sweet potatoes while you peel and slice the carrots. Add the carrots to the pan as you chop them.

Next, add the chicken stock to the pan, stir to combine, place the lid on top, and turn the heat up to medium-high.

Allow the soup to come to a boil, then turn the heat down to low and allow it to simmer for about 30 minutes, stirring every now and then.

After 30 minutes the sweet potatoes and carrots should be extremely soft and they should be starting to fall apart.

Turn the heat off and remove the pan from the hob to help it cool down quicker.

Add the coconut milk and stir to combine. You can reserve a tablespoon or two of the coconut milk to garnish the finished soup, if you like.

Use an immersion blender, or allow the soup to cool further and carefully purée in batches using a traditional blender. Once the soup is puréed, give it a taste and add salt or pepper if desired. Depending on the stock you've used, there's a good chance that it will be salty enough. Garnish your Spicy Carrot & Sweet Potato Soup with fresh coriander and chilli sauce, if desired.