Once the water is up to a rolling boil, cover the cashews in the water in a sturdy bowl. Add the chopped carrot to the pot and continue to boil them until fork tender.
While the carrots are boiling add all the (non-optional) ingredients to a high speed blender.
Once carrots are soft and the cashews have soaked in the hot water (about 10-15 minutes) add them to the blender and blend until smooth.
Taste and adjust for seasoning.
At this point you can either eat this as is, or you can add some of the optional ingredients. I've tried it with all of them and it's super good no matter what! So just experiment and add a little bit at a time until you get the results that you want.