Place all the ingredients that need cooking into a large stock pot and bring to a boil. Cook with a vented lid for about 15 minutes at a steady, medium boil.
While that cooks, place all blending ingredients into a blender and blend until totally smooth. Note that if you don't have a high-powered blender, you may end up having a small amount of texture in the cashew cream. It's not bad, just a texture difference worth noting. Your chowder will just have more texture from the nuts.
When the cooking ingredients are cooked through (the potatoes are totally cooked and soft), remove from heat and stir in the cashew cream.
Season the chowder with salt and pepper as needed and serve garnished with fresh, sliced, green onions.
Notes
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.