Easy Vegetarian Corn Chowder

1 T olive oil
2 c diced white onions
11/2 c diced celery
1/2 c diced carrot
3/4 c diced bell pepper (red, green, or yellow)
4 c peeled, cubed potatoes
1/4 t sage
8 c water (or enough to cover veggies by 1/2 inch)
2 T miso or powdered broth
3 c corn
3 T minced green onion
Saute onion, celery, carrot, and pepper in oil until they begin to soften. Add potatoes and sage; Mix well and saute an additional 3 minutes.
Add water, bring to a boil and simmer over medium heat 10-15 minutes, until potatoes are tender.
Remove 1/2 c of broth and dissolve miso in it. Add to soup and mix well.
Remove 1/3 of sour with lots of veggies in it and set aside. Blend remaining soup until smooth in blender or food processor. Stir in reserved soup, corn, and green onion.
Bring to a boil, stirring frequently, and simmer 10 minutes on low heat.