Sweet Potato, Coconut and Lime Soup

1 large white onion peeled and diced
2 garlic cloves peeled and crushed or finely sliced
2 tbsp sunflower oil
1 fresh red chilli deseeded and finely sliced
2 large sweet potatoes peeled and diced
½ tsp black pepper
1 and ½ tsp salt
1 litre vegetable or chicken stock
400ml coconut milk
1 lime zest and juice
Pinch chilli flakes to serve

Heat oil in a large heavy bottomed saucepan over a high heat, add onions and cook to soften. Add garlic and chilli and cook for further 2 minutes.
Add the diced potatoes, salt and pepper. Reduce the heat and cook for 5 minutes stirring occasionally.
Add stock and coconut milk and simmer until potatoes are soft and cooked through.
Remove from the heat, add lime juice and blend until smooth.
Ladle soup into warm bowls and serve topped with chilli flakes and lime zest