Heat olive oil in a large pot.
Add the carrots, leeks, celery, onions, garlic and ginger and saute for 10 minutes over medium heat, stirring frequently
Add the shiitake mushrooms, parsley, basil and 8 cups water.
Season with salt and pepper.
Turn heat to high and bring to a boil, then reduce the heat to medium-low and simmer, covered for 20 minutes.
Serve in a bowl or mug and garnish with chives.
Serves 5