Heat oil in a soup pot over medium-low heat.

Add curry paste and onions, cook for 4 minutes, stirring occasionally.

Reduce heat if necessary.

Add garlic and ginger, cook for 1-2 minutes.

Add sweet potatoes and pepper, mix well.

Add stock and cook for 15 minutes, or until vegetables are soft.

Puree the soup in batches using a blender or with an immersion blender.

Check the consistency and add more stock or water if needed.

Adjust seasonings, adding salt or more curry paste if desired (cook paste first).

Add rum if using.

Serve in bowls and top with sour cream and paprika.