Put a pan over medium heat and warm oil. Add onion, carrots, celery and stir. Reduce the heat and cook with a lid about 10 mins or until they get soft. Don't forget to stir occasionally.

Add broth, bay leaf, oregano, sweet potato and drained navy beans then cover with a lid. Bring it to a boil, reduce the heat and simmer about 15 mins.

Add napa and green onion and continue to cook another 10 mins. Add some more water if needed.

Salt and pepper to taste and enjoy your hearty warm soup!