Squash and two potato soup

Why I Love This Recipe
Just threw this together today, and I'm really happy with it! Vegetables can be added in different proportions; this is just what I was able to get easily at the store.
Ingredients You'll Need
1 tablespoon olive oil
1 medium onion, chopped
1-2 cloves garlic, minced*
6 cups water
1 tablespoon vegetarian soup base
1.25 lbs. white potatoes, cut into eighths
1 lb. sweet potatoes, peeled and chopped*
1.25 lbs. butternut squash, peeled and chopped*
1/8 teaspoon celery salt
1/4 teaspoon dried tarragon
pepper to taste
*I used prepared minced garlic and pre-peeled and chopped sweet potatoes and squash
Directions
Heat oil in a dutch oven.
Saute onion until translucent.
Add garlic and cook for about 1 minute.
Add water and soup base, stirring to combine.
Add white potatoes and bring to a boil.
Add sweet potatoes and squash.
Simmer until all vegetables are soft enough to puree.
Remove from heat and allow to cool slightly.
Puree soup in batches, or with an immersion blender.
Makes about 3 quarts.